Low-crystallized carbon materials for lithium-ion secondary batteries

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考试复习笔记-材料概论(上)

Chromium additions produce stainless steels for corrosion resistance .
加入铬添加剂可以生产耐腐蚀的不锈钢。
Additions such as tungsten lead to high-hardness alloy used as tool steels .
加入钨之类的添加剂可以生产用做工具刚的高硬度合金。
superalloys include many stainless steels that combine corrosion resistance with high strength at elevated temperatures .
超合金包括多种不锈钢，这些不锈钢在高温下即耐腐蚀同时又具有高强度。
超过90%重量的工程材料是铁基合金，包括刚（含0.05～2.0 wt% C）和铸铁（含2.0～4.5 wt% C）。
Most steels involve a minimum of alloy additions to maintain moderate costs .
大多数的刚只含有少量的合金添加剂使材料的成本适中。
要理解这各种材料的性能需要从微观或亚微观尺度上研究材料的结构。
2、
The relative ductility of certain metal alloys is related to atomic-scale "architecture".
某些金属合金的延展性的相对大小与其原子尺度上的“构造有关。
当我们了解了材料的性能，材料的实际选择就可以在两个层次上进行。
First ,there is competition among the various categories of materials .

DAB 193 中央气动泵说明书

DAB PUMPS reserves the right to make modifications without notice193C E N T R I F U G A L P U M P SCast iron discharge and suction bodies treated against corrosion. Technopolymer impellers, diffuser bodies and diffusers. AISI 304 stainless steel pump liner and wear rings. AISI 416 stainless steel pump shaft and AISI 316 stainless steel sliding bush. Bronze sliding bush guide, self-lubricated by the pumped liquid itself.Carbon/ceramic m echanical s eal. C onnected t o t he m otor with a rigid coupling.Supplied standard with threaded counterflanges. Induction motor, closed and cooled with external ventilation. Rotor mounted on oversized greased sealed-for-life ball bearings to ensure silent running and long life. Built-in thermal and current overload protection in the single-phase version. Three-phase motors should be protected with a suitable overload protection complying with the regulations in force.Operating range: from 1,8 to 13,5 m3/h with head up to 139 metres.Liquid temperature range:from 0°C to +35°C for domestic usefrom -15°C to +110°C for other usesLiquid quality requirements: clean, free from solids or abrasive substances, non viscous, non aggressive, non crystallized, chemically neutral, close to the characteristics of water..Maximum ambient temperature: + 40°C Maximum operating pressure: 18 bar (1800 kPA) Motor protection: IP 55Insulation class: FInstallation: fixed, in a vertical position.KV 3/6/10。

Synthesis and Characterization of Li(Li0.23Mn0.47Fe0.2Ni0.1)O2 Cathode Material for Li-ion Batteries

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Li(Li0.23Mn0.47Fe0.2Ni0.1)O2 compound synthesized easily at low temperature by the proposed citric acid assisted sol-gel process is a promising cathode material for Li-ion batteries.
57
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(1−z)Li[Li1/3Mn2/3]O2−(z)Li[Mn0.5−yNi0.5−yCo2y]O2
M AN U
[11]. to
2
Li2MnO3–LiCo1/3Ni1/3Mn1/3O2
SC
The 4.0~4.5V)
storage power station applications. Therefore, new cathode materials with high capacity, low cost and environment friendly have been investigated thoroughly in recent years [1]. Among them the layered Li2MnO3-based solid solution materials have attracted more attention of the researchers, such as Li2MnO3-LiMO2 (M = Ni, Cr and Co) [2–5], LiNiO2–Li2MnO3–LiCoO2 [8], and [6], Li2MnO3–LiNi1−xCoxO2 [7], [9], [10], above-mentioned

关于磷酸铁锂的英文文献(含中文翻译)

Preparation and characterization of carbon-coated LiFePO 4cathode materials for lithium-ion batteries with resorcinol –formaldehyde polymer as carbon precursorYachao Lan,Xiaodong Wang ⁎,Jingwei Zhang,Jiwei Zhang,Zhishen Wu,Zhijun Zhang ⁎Key Laboratory for Special Functional Materials,Henan University,Kaifeng 475004,Chinaa b s t r a c ta r t i c l e i n f o Article history:Received 8February 2011Received in revised form 26May 2011Accepted 3June 2011Available online 12June 2011Keywords:Lithium iron phosphateResorcinol –formaldehyde polymer Lithium-ion batteryLiFePO 4/C composites were synthesized by two methods using home-made amorphous nano-FePO 4as the iron precursor and soluble starch,sucrose,citric acid,and resorcinol –formaldehyde (RF)polymer as four carbon precursors,respectively.The crystalline structures,morphologies,compositions,electrochemical performances of the prepared powders were investigated with XRD,TEM,Raman,and cyclic voltammogram method.The results showed that employing soluble starch and sucrose as the carbon precursors resulted in a de ﬁcient carbon coating on the surface of LiFePO 4particle,but employing citric acid and RF polymer as the carbon precursors realized a uniform carbon coating on the surface of LiFePO 4particle,and the corresponding thicknesses of the uniform carbon ﬁlms are 2.5nm and 4.5nm,respectively.When RF polymer was used as the carbon precursor,the material showed the highest initial discharge capacity (138.4mAh g −1at 0.2C at room temperature)and the best rate performance among the four materials.©2011Elsevier B.V.All rights reserved.1.IntroductionLiFePO 4is an attractive cathode material for lithium-ion batteries because of its high theoretical capacity of 170mAh g −1,environ-mental benign,and high thermal stability.However,its poor electric conductivity of less than 10−13S cm −1limits its battery performance [1],such as the dramatic decrease in power at a high current density,which is the main drawback to commercial use.To overcome the low electric conductivity of LiFePO 4,many effective approaches have been introduced,including metal substitution [2–5],metal powder com-pounding [6],and conductive carbon coating [7–15].Among them,the preparation of LiFePO 4/carbon composite (LiFePO 4/C)is one of the attractive ways to improve the electric conductivity of the ﬁnal product by forming a good conduction path.Furthermore,carbon can be also used as a reductant,which can reduce Fe 3+ions to Fe 2+ions.It should be noted that many studies involving the synthesis of nano-sized LiFePO 4employ Fe 2+salts as precursors [3,16–20],such as FeC 2O 4·2H 2O and (CH 3COO)2Fe,which are expensive.Therefore,it is necessary to use cheap materials and a convenient method.Here,we report the synthesis,characterization and electrochemical test of LiFePO 4/C composites prepared by two methods using home-made amorphous nano-FePO 4as the iron precursor and various organics as carbon precursors.The two methods using FePO 4as starting material are cheap and environmentally benign for the production of LiFePO 4material.Particularly,we present a novel method to synthesize a uniformcarbon ﬁlm coated LiFePO 4cathode materials.This method involved an in situ reaction of resorcinol and formaldehyde on the surface of amorphous FePO 4.At room temperature,electrochemical tests showed that this material exhibited an initial discharge capacity of 138.4mAh g −1at 0.2C and a good cycling property at 0.5and 1.0C rate,respectively.2.Experimental2.1.Preparation of amorphous nano-FePO 4Amorphous nano-FePO 4was prepared by spontaneous precipita-tion from aqueous solutions.An equimolar solution of H 3PO 4was added to a solution of Fe(NO 3)3·9H 2O at 60°C under stirring and given amounts of PEG-400as surfactant.Then ammonia water (NH 3·H 2O)was slowly added to the mixed solution under vigorous stirring and a milk-white precipitate formed immediately.The pH of the solution was kept at 2.0.The precipitate was ﬁltered and washed several times with distilled water.After drying in vacuum oven at 120°C for 12h,yellowish-white amorphous FePO 4was obtained.2.2.Preparation of LiFePO 4/CTwo methods were used to prepare the LiFePO 4/C composites in this study.2.2.1.Method oneA rheological phase method [21]was employed to synthesize LiFePO 4/C composite.Stoichiometric amount of amorphous FePO 4,LiOH·H 2O were used as the starting materials.The carbon precursorsPowder Technology 212(2011)327–331⁎Corresponding authors.Tel./fax:+863783881358.E-mail address:donguser@ (X.Wang).0032-5910/$–see front matter ©2011Elsevier B.V.All rights reserved.doi:10.1016/j.powtec.2011.06.005Contents lists available at ScienceDirectPowder Technologyj o u r n a l h o me p a g e :w w w.e l sev i e r.c o m /l oc a t e /pow t e care soluble starch(50.0g/1mol LiOH·H2O),sucrose(35.0g/1mol LiOH·H2O),citric acid monohydrate(21.0g/1mol LiOH·H2O),respec-tively.These carbon precursors were respectively solved in an appropri-ate amount of distilled water under stirring and heating.Then the amorphous FePO4and LiOH·H2O were added under vigorous stirring. Subsequently,the mixtures were respectively dried in an oven at120°C for6h,heated at350°C for1h in argonﬂow,treated at750°C for12h in argonﬂow,and ground.Finally,the LiFePO4/C composites were obtained and were denoted as sample A,sample B and sample C,respectively. 2.2.2.Method twoIn a typical synthesis,0.10g of CTAB was solved in30ml of distilled water solution under continuous stirring.Subsequently,1.52g FePO4·3H2O,0.055g resorcinol(R)and0.10ml formaldehyde(F)were successively added.When the temperature of water bath was up to85°C,LiOH·H2O was added.The mixture was kept stirred up in the dark for2h,dried in an oven at120°C for6h,heated at 350°C for1h in argonﬂow,treated at750°C for12h in argonﬂow, andﬁnally ground to obtain the LiFePO4/C composites(denoted as sample D).These four samples and their corresponding parameters are listed in Table1.The carbon contents of the samples were calculated by the loss on ignition of the four LiFePO4/C composites in air.2.3.CharacterizationThermogravimetric(TG)and differential thermal analysis(DTA) analyses were conducted with an EXSTAR6000thermal analysis system at a heating rate of10°C min−1.The powder X-ray diffraction (XRD,X'Pert Pro MPD,Philips)using Cu Ka radiation was employed to identify the crystalline phase of the prepared materials.Raman spectrum was recorded on a Renishaw RM-1000Microscopic Raman spectrometer with457.5nm excitation requiring a10mW power at room temperature.Low-magniﬁcation and high-magniﬁcation TEM images were taken on a JEM-2010transmission electron microscope (using an accelerating voltage of200kV).Electrodes were fabricated from a mixture of prepared carbon-coated LiFePO4powders(80wt.%),carbon black(12wt.%),and polyvinylideneﬂuoride in N-methylpyrrolidinon(8wt.%).The slurry was spread onto Al foil and dried in vacuum at120°C for12h.The carbon-coated LiFePO4loading was2mg cm−2in the experimental cells.The cells were assembled in an argon-atmosphere-ﬁlled glove box.The electrolyte was1M LiPF6in a mixture of ethylene carbonate (EC)and dimethyl carbonate(DMC)(1:1volume).The cells were galvanostatically charged and discharged at a voltage range of2.5–4.2V with LAND battery testing system at room temperature.Cyclic voltammograms were run on an IM6impedance and electrochemicalmeasurement system(Zahner,Germany)at a scan rate of0.1mV s−1 between2.5and4.0V.3.Results and discussionThe TEM images of the amorphous nano-FePO4were shown in Fig.1.The morphology of the as-prepared FePO4is an irregular particle with an average diameter of30nm.Most of the particles connected to each other because of their high surface energy which results from their small sizes.Fig.2a shows the TG/DTA curves of the FePO4·3H2O powder with a heating rate of10°C/min from room temperature to850°C in air.On the DTA curve near150°C,there is a very strong endothermic peak, associating with the sharp weight loss on the TG curve,which is related to the quick dehydration of FePO4·3H2O.During150–550°C, 26.3%weight loss on the TG curve indicates the slow elimination of residual H2O in FePO4·3H2O,exactly corresponding to the loss of crystalline water of FePO4·3H2O.And one exothermic peak is displayed at a higher temperature of590°C,which is not accompa-nied by appreciable weight loss in the TG curve,indicating the transformation of the amorphous FePO4to hexagonal FePO4crystal. The XRD patterns of FePO4·3H2O before and after calcination have been investigated in Fig.2b.As illustrated in pattern A,it can be seen that there is no evidence of diffraction peaks before calcination, indicating the synthesized FePO4·3H2O is just amorphous.While for the calcinated FePO4·3H2O at600°C for6h in air,it exhibits strong and narrow peaks revealing a well-crystallized material in pattern B. All of the diffraction peaks of the prepared FePO4are indexed to a single-phase hexagonal structure with a P3121space group and without any impurities,which is in good agreement with the standard card(JCPDS card no:72–2124).Table1Carbon precursors and residual carbon content of samples A,B,C and D.Samples A B C DCarbon precursor Starch Sucrose Citric acid RF polymer Final carbon content(wt.%) 5.48.5 4.35.1Fig.1.TEM images of the prepared amorphous nano-FePO4.n et al./Powder Technology212(2011)327–331The XRD diffraction patterns of LiFePO 4/C powders prepared with different carbon precursors were shown in Fig.3.All peaks can be indexed as a single phase with an ordered olivine structure indexed to the orthorhombic space group,Pnmb (JCPDS card no.83–2092).The obtained lattice parameters are sample A:a=10.2956Å,b=6.0367Å,and c =4.7001Å,sample B:a =10.1992Å,b =6.0483Å,andc=4.6971Å,sample C:a=10.2472Å,b=6.0208Å,and c=4.6882Åand sample D:a=10.3372Å,b=5.9993Å,and c=4.6932Å,respec-tively.There is no evidence of diffraction peaks for carbon,though some amorphous masses and ﬁlms attached to the LiFePO 4particles were observed from TEM images (see Fig.4).This indicates the carbon contents are very low.Morphologies of these LiFePO 4/C composites were shown in Fig.4.It is obvious that the samples show different carbon distribution on LiFePO 4particle surface.From Fig.4a,c,e and g,we observed that the samples were composed of agglomerated particles whose sizes range from 50to 300nm.From Fig.4b and d,there is not enough carbon coating to spread throughout the substrate particles.In contrast to sample A and sample B,there are uniform carbon thin ﬁlms on the grain surfaces of sample C and sample D,and the thickness of the carbon ﬁlms are about 2.5nm (Fig.4f)and 4.5nm (Fig.4h),respectively.The reason may lie in that different carbon precursors have different adsorbabilities on the surface of FePO 4·3H 2O particles,resulting in different carbon distribution on the surface of LiFePO 4particle after the post treatment.Soluble starch and sucrose possess plentiful hydroxyl groups,by which soluble starch and sucrose molecules could probably weakly adsorb on the surface of FePO 4·3-H 2O particles in the hydrogen bonding.In the post treatment process,part of soluble starch and sucrose molecules desorbed from the surface of FePO 4·3H 2O particles,resulting in the de ﬁcient carbon coating.But citric acid possesses carboxyl groups,which may be partially esteri ﬁed by hydroxyl groups on the FePO 4·3H 2O particles,forming a tight connection.This results in more complete carbon coating after the post treatment.For sample D,we suppose that,in the present synthetic system,the surfactant CTAB may con ﬁne the resorcinol –formaldehyde (RF)polymer molecules and FePO 4·3H 2O particles in plenty of tiny spaces,so the RF polymer molecules were tightly attached to FePO 4·3H 2O particles.After the post treatment,the RF polymer was transformed into the carbon ﬁlm which tightly stuck on the surface of LiFePO 4particle.In addition,from the HRTEM image of sample D (shown in Fig.4h),the d-spacing of 0.294nm corresponds to the (211)plane of LiFePO 4.As an important aid investigating the structure of the carbon,the Raman measurement was adopted,and the results were shown in Fig.5.Every Raman spectrum consists of a small band at 940cm −1,which corresponds to the symmetric PO 4stretching vibration in LiFePO 4.The intense broad bands at 1350and 1590cm −1can be attributed to the characteristic Raman spectra of carbon.The bands at 1590cm −1mainly correspond to graphitized structured carbon of G band,while that at 1350cm −1corresponds to disordered structured carbon of D band [22,23].The graphitized carbon contains sp 2hybrid bonding,which is positively correlated with the electronic conduc-tivity of carbon,and the disordered carbon mainly corresponds to sp 3hybrid bonding.As shown in Fig.5,the integrated intensity ratios of sp 2/sp 3of the LiFePO 4/C composites synthesized with different carbon precursors are 0.865(curve A),0.857(curve B),0.856(curve C)and 0.860(curve D),respectively.So the similar sp 2/sp 3ratios of the four samples give us few clues to explain the difference in their electrochemical performances.Fig.6shows the cycling performance curves of all the samples at different rates.As shown in Fig.6,the initial discharge capacities of sample A,sample B,sample C and sample D at room temperature at 0.2C rate are 110.4,118.8,137.7and 138.4mAh g −1,respectively.The capacity of sample D gradually increases in the initial cycles.This may be due to the incomplete dispersion of the electrolyte into the electrode material at the beginning.Moreover,the capacity of sample D is highest among the four samples at 0.5C and 1.0C,indicating that method two is better than method one.The lower capacities of sample A and sample B must be due to the incomplete carbon coating on the LiFePO 4particles.The higher capacity of sample D than that of sample C may be attributed to the thicker carbon ﬁlm of sample D keeping the crystal structure of LiFePO 4morestable.Fig.2.(a)TG/DTA curves of the FePO 4·3H 2O.(b)XRD patterns of the FePO 4samples before (A)and after (B)calcination inair.Fig. 3.XRD patterns of LiFePO 4/C composites synthesized with different carbon precursors.329n et al./Powder Technology 212(2011)327–331In order to further understand the electrochemical properties of the four samples,the cyclic voltammogram (CV)curves were performed at a scan rate of 0.1mV s −1at room temperature (as shown in Fig.7).Each of the CV curves consists of an oxidation peak and a reduction peak,corresponding to the charge reaction and discharge reaction of the Fe 2+/Fe 3+redox couple.In the CV pro ﬁles of the LiFePO 4cathode material,the smaller voltage difference between the charge and discharge plateaus and the higher peak current means better electrode reaction kinetics,and consequently better rate performance.Sample A and sample B electrodes have broad peaks in CV curves.In contrast,sample C and sample D electrodes demonstrate sharp redox peaks,which indicate an improvement in the kinetics of the lithium intercalation/de-intercalation at the electrode/electrolyte interface.The voltage difference of sample D is smaller than that of sample C,so sample D demonstrates a better rate performance.4.ConclusionsLiFePO 4/C composites were synthesized by two methods using home-made amorphous nano-FePO 4as the iron precursor and various organics as carbon precursors.It was found that employing soluble starch and sucrose as the carbon precursors resulted in a de ﬁcient carbon coating on the surface of LiFePO 4particle,but employing citric acid and RF polymer as the carbon precursors realized a uniform carbon coating on the surface of LiFePO 4particle.Particularly,when RF polymer was used as the carbon precursor,the carbon ﬁlm is thicker,and the material showed the highest initial discharge capacity (138.4mAh g −1at 0.2C at room temperature)and the best rate performance among the four materials.The intensities of redox peak and the voltage differences in the CV curves of the four samples are consistent with their rateperformance.Fig.4.TEM images of synthesized LiFePO 4/C composite synthesized with different carbon precursors.(a)and (b)sample A,(c)and (d)sample B,(e)and (f)sample C,(g)and (h)sampleD.Fig. 5.Raman shift of LiFePO 4/C composites synthesized with different carbonprecursors.Fig.6.The cycling performance curves of the samples with different carbon precursors at various discharge rates.n et al./Powder Technology 212(2011)327–331References[1] A.K.Padhi,K.S.Nanjundaswamy,J.B.Goodenough,Phospho-olivines as positive-electrode materials for rechargeable lithium batteries,J.Electrochem.Soc.144(1997)1188–1194.[2]T.Nakamura,Y.Miwa,M.Tabuchi,Y.Yamada,Structural and surfacemodi ﬁcations of LiFePO 4olivine particles and their electrochemical 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composites,J.Electrochem.Soc.152(2005)A607-A607.[14]K.Zaghib,J.Shim,A.Guer ﬁ,P.Charest,K.A.Striebel,Effect of carbon source asadditives in LiFePO 4as positive electrode for lithium-ion batteries,Electrochem.Solid-State Lett.8(2005)A207–A210.[15]K.S.Park,J.T.Son,H.T.Chung,S.J.Kim,C.H.Lee,K.T.Kang,H.G.Kim,Surfacemodi ﬁcation by silver coating for improving electrochemical properties of LiFePO 4,Solid State Commun.129(2004)311–314.[16] A.Yamada,S.C.Chung,K.Hinokuma,Optimized LiFePO 4for lithium batterycathodes,J.Electrochem.Soc.148(2001)A224–A229.[17]N.Meethong,H.-Y.Shadow Huang,W.C.Carter,Y.-M.Chiang,Size-dependentlithium miscibility gap in nanoscale Li 1−x FePO 4,Electrochem.Solid-State Lett.10(2007)A134–A138.[18] C.Delacourt,P.Poizot,S.Levasseur,C.Masquelier,Size effects on carbon-freeLiFePO 4powders,Electrochem.Solid-State Lett.9(2006)A352–A355.[19] D.Choi,P.N.Kumta,Surfactant based sol –gel approach to nanostructured LiFePO 4for high rate Li-ion batteries,J.Power Sources 163(2007)1064–1069.[20]K.Zaghib,A.Mauger,F.Gendron,C.M.Julien,Surface effects on the physical andelectrochemical properties of thin LiFePO 4particles,Chem.Mater.20(2008)462–469.[21]Y.H.Huang,H.B.Ren,S.Y.Yin,Y.H.Wang,Z.H.Peng,Y.H.Zhou,Synthesis ofLiFePO 4/C composite with high-rate performance by starch sol assisted rheolog-ical phase method,J.Power Sources 195(2010)610–613.[22]M.M.Doeff,J.D.Wilcox,R.Kostecki,u,Optimization of carbon coatings onLiFePO 4,J.Power Sources 163(2006)180–184.[23]G.L.Yang,A.F.Jalbout,Y.Xu,H.Y.Yu,X.G.He,H.M.Xie,R.S.Wang,Effect ofpolyacenic semiconductors on the performance of olivine LiFePO 4,Electrochem.Solid-State Lett.11(2008)A125–A128.Fig.7.The CV pro ﬁles of the different samples at the scan rate of 0.1mV s −1.331n et al./Powder Technology 212(2011)327–331。

住宅产业化进程中的设计初探之

住宅产业化进程中的设计初探之摘要：回顾世界发展历史，为了解决吃饭、穿衣、住房子这三件大事中“住”的问题，人类创造了各种形式的经典建筑，这些建筑便是人类生生不息的文明足迹，更是“时代的缩影”、“石头的史诗”，兼有物质产品和精神文化结晶的双重社会价值。

而随着社会的发展，人民生活水平的提高，农村城市化进程的加速，市场需求的不断增长使得我国住宅产业还有着很大的发展空间，住宅业发展到一定阶段必然会出现住宅产业化。

包含科技改造、企业整合和工业化生产及自我循环等内容的住宅产业化是实现我国住宅生产方式由粗放型向集约型的根本转变。

2009年哥本哈根气候大会的召开，使“低碳”成为国内各行各业讨论的新话题，中国政府也正式承诺要减少碳的排放，提出要发展循环经济，建设资源节约环境友好型社会。

目前我国住宅产业的粗放式的生产方式，导致其碳排放量巨大且资源浪费严重，而住宅产业化可以实现房屋建设过程中的低碳的生产方式，被视为是最有力的节能手段。

因此，住宅产业必需朝产业化方向发展。

关键词：住宅产业化;节能设计;设计初探;对策;经济效益summary: review the history of world development, in order to solve the problems of food, clothing, housing sub-three big “live”, mankind has created various forms of classical architecture, these buildings is a civilized human perennial footprint, moreis a microcosm of the times, “stone epic, bothmaterial and spiritual culture crystallized double social value. with the development of society, people’s living standards improve, the acceleration of the process of urbanization in rural areas, the growing market demand makes china’s housing industry still has much room for development, the development of the housing industry is bound to a certain stage of housing industrialization. the housing industry is technological transformation, enterprise integration, and industrial production and self-cycle content to achieve our the residential production methods fundamental shift from extensive to intensive. the 2009 copenhagen climate conference, “low carbon”become a new topic for discussion by the domestic industries, the chinese government is also a formal commitment to reduce carbon emissions, proposed to develop recycling economy and building a resource-saving and environment-friendly society. china’s housing industry’s extensive production methods, resulting in huge carbon emissions and serious waste of resources, and the industrialization of residential housing construction process can achieve low-carbon mode of production, is regarded as the most powerful means of energy conservation. therefore, the housing industry is necessary for thedevelopment direction of industrialization.key words: residential industrialization; energy-saving design; design preliminary; countermeasures; economic benefits中图分类号：tu201.5 文献标识码：a 文章编号：2095-2104（2012）1.住宅产业和住宅产业化的概念1.1住宅产业（housing industry）的概念是日本通产省于1968年首次提出的，指标准产业分类的各产业领域中与住宅相关的各行业的总和。

碳酸钠、氢氧化钠与水玻璃复合激发对地聚物胶凝材料性能的影响

第43卷第3期2024年3月硅㊀酸㊀盐㊀通㊀报BULLETIN OF THE CHINESE CERAMIC SOCIETY Vol.43㊀No.3March,2024碳酸钠㊁氢氧化钠与水玻璃复合激发对地聚物胶凝材料性能的影响蒋明屾,李㊀飞,周理安,宁佳蕊,张㊀政(北京建筑大学,北京节能减排与城乡可持续发展省部共建协同创新中心,北京㊀100044)摘要:采用碳酸钠替代氢氧化钠调节水玻璃模数制备复合碱激发剂,研究不同碱掺量下碳酸钠掺入比例对地聚物胶凝材料净浆流动度㊁凝结时间及抗压强度的影响,并通过FT-IR㊁XRD 和SEM 试验分析地聚物胶凝材料水化产物的物相组成及微观形貌㊂结果表明,氢氧化钠与碳酸钠共同复合水玻璃的激发剂激发效果优于二者单独与水玻璃复合的激发剂,当碱掺量为6%(质量分数)㊁碳酸钠替代比例为40%(质量分数)时,地聚物胶凝材料净浆流动度为185mm,28d 抗压强度为94.4MPa㊂碳酸钠替代比例增加可延长地聚物胶凝材料凝结时间,当替代比例为100%时,地聚物胶凝材料初凝时间㊁终凝时间可达372和420min㊂不同碱组分激发剂作用时,地聚物胶凝材料水化产物相似,均以无定形铝硅酸盐C-(A)-S-H 凝胶为主㊂关键词:复合碱激发剂;地聚物;流动度;凝结时间;抗压强度中图分类号:TU528㊀㊀文献标志码:A ㊀㊀文章编号:1001-1625(2024)03-0929-09Effects of Sodium Carbonate ,Sodium Hydroxide and Water Glass Composite Activation on Properties of Geopolymer Cementitious MaterialsJIANG Mingshen ,LI Fei ,ZHOU Li an ,NING Jiarui ,ZHANG Zheng(Beijing Collaborative Innovation Center for Energy Saving and Emission Reduction and Urban-Rural Sustainable Development,Beijing University of Civil Engineering and Architecture,Beijing 100044,China)Abstract :Composite alkali activator was prepared by using sodium carbonate instead of sodium hydroxide to adjust the modulus of water glass.The effects of different alkali content and sodium carbonate replacement ratio on fluidity,setting time,and compressive strength of geopolymer cementitious materials were studied.The phase composition and microstructure of hydration products of geopolymer cementitious materials were analyzed through FT-IR,XRD,and SEM experiments.The results show that the combined effects of sodium hydroxide and sodium carbonate combined with composite water glass activators are superior to the effects of their individual combined with water glass activators.When alkali content is 6%(mass fraction)and the replacement ratio of sodium carbonate is 40%(mass fraction),the fluidity of geopolymer cementitious materials reaches 185mm,and 28d compressive strength reaches 94.4MPa.The increase of replacement ratio of sodium carbonate can prolong the setting time of geopolymer cementitious materials.When the replacement ratio reaches 100%,the initial setting time and final setting time of geopolymer cementitious materials reach372and 420min.When different alkali components are used as activators,similar hydration products are observed in geopolymer cementitious materials,mainly consist of amorphous aluminosilicate C-(A)-S-H gel.Key words :composite alkali activator;geopolymer;fluidity;setting time;compressive strength 收稿日期:2023-09-12;修订日期:2023-11-22基金项目:国家重点研发计划(2022YFC3803404);北京市西城区财经科技专项资助项目(XCSTS-TI2022-12)作者简介:蒋明屾(1999 ),男,硕士研究生㊂主要从事建筑材料㊁地聚物材料方面的研究㊂E-mail:jimish1999@通信作者:李㊀飞,博士,教授㊂E-mail:lifei@0㊀引㊀言随着城镇化建设的推进和基础设施的迅速发展,我国混凝土用量占世界年产量的一半以上,传统硅酸盐930㊀资源综合利用硅酸盐通报㊀㊀㊀㊀㊀㊀第43卷水泥作为制备混凝土的常用材料,其制备工业属于高消耗和高排放行业,硅酸盐水泥生产相关的CO2排放量占全球人为CO2排放量的5%~10%[1-2],降低水泥混凝土行业的碳排放是我国实现双碳目标的关键环节之一㊂近年来,地聚物胶凝材料因具有利废㊁节能㊁减碳等特点,受到高度关注,其制备工艺简单,无需高温煅烧,兼具良好的力学性能和耐久性能[3-5],极有可能成为替代水泥的绿色新型胶凝材料㊂地聚物胶凝材料常用的激发剂主要是水玻璃㊁氢氧化钠和碳酸钠,采用上述单一激发剂激发时效果均不理想,因此一般采用氢氧化钠调节水玻璃模数制备复合碱激发剂,但氢氧化钠-水玻璃复合碱激发剂存在凝结时间过快㊁碱度大㊁成本高等缺点,限制了其在实际工程领域的应用㊂碳酸钠是一种强碱弱酸盐,与氢氧化钠相比具有较低的pH值,价格低廉且更加环保,一些研究[6-9]表明在激发剂中引入碳酸钠有利于地聚物胶凝材料力学性能的发展,但也存在凝结硬化时间过长㊁强度发展非常缓慢等问题[10-11]㊂目前对于碳酸钠与氢氧化钠共同调节水玻璃模数制备复合碱激发剂的系统研究并不常见㊂氢氧化钠复合水玻璃激发地聚物存在凝结时间过短的问题,而碳酸钠激发地聚物存在凝结时间过长的问题,若采用水玻璃㊁氢氧化钠与碳酸钠混合作为激发剂可获得理想的凝结时间㊂本试验采用氢氧化钠与碳酸钠复合水玻璃制备碱激发剂,研究复合碱激发剂对地聚物胶凝材料净浆流动度㊁凝结时间及抗压强度的影响,借助FTIR㊁XRD与SEM微观测试技术进一步分析水化产物的组成及形貌,并对宏观性能作出解释㊂1㊀实㊀验1.1㊀原材料矿渣:市售S95矿渣粉,白色粉末,密度为2.89g/cm3,流动度为102%,烧失量为0.13%,7d活性指数为80%,28d活性指数为95%;根据化学组成计算[12],质量系数K=2.21,碱性系数M0=1.32,活性系数M a=0.45㊂粉煤灰:河南远恒环保工程有限公司生产的Ⅱ级粉煤灰,灰黑色粉末,密度为2.28g/cm3,需水量为97%,烧失量为2.86%,活性指数为77%㊂矿渣与粉煤灰的主要化学组成见表1,XRD谱见图1,粒径分布见图2㊂表1㊀矿渣与粉煤灰的主要化学组成Table1㊀Main chemical composition of slag and fly ashMaterial Mass fraction/%CaO SiO2Al2O3MgO Fe2O3TiO2SO3K2O Na2O MnO Other Slag46.4227.8812.43 6.790.42 1.45 2.710.700.550.370.28 Fly ash 5.5252.9928.750.78 5.85 1.280.71 2.760.680.100.58图1㊀矿渣与粉煤灰的XRD谱Fig.1㊀XRD patterns of slag and fly ash激发剂采用水玻璃㊁氢氧化钠㊁碳酸钠,试验用水玻璃为浙江省嘉兴市嘉善县优瑞耐火材料有限公司生第3期蒋明屾等:碳酸钠㊁氢氧化钠与水玻璃复合激发对地聚物胶凝材料性能的影响931㊀产的钠水玻璃,无色透明黏稠液体,技术指标见表2㊂氢氧化钠为片状NaOH,纯度不小于98%,碳酸钠为颗粒状Na 2CO 3,纯度不小于99.8%㊂图2㊀矿渣与粉煤灰的粒径分布Fig.2㊀Particle size distribution of slag and fly ash表2㊀水玻璃的技术指标Table 2㊀Technical indicators of water glassModulus Na 2O content /%SiO 2content /%Solid content /%Concentration /ʎBéDensity /(g㊃cm -3)2.2513.7529.9943.5050 1.5㊀㊀Note:%represents mass fraction.1.2㊀配合比本试验固定水玻璃模数M s =1.2(即激发剂中SiO 2与Na 2O 物质的量之比为1.2),采用Na 2CO 3替代NaOH 调节水玻璃模数至1.2,替代比例为0%~100%(质量分数),碱掺量为4%㊁6%㊁8%(按激发剂中总Na 2O 质量占地聚物胶凝材料质量百分比计)㊂胶凝材料中矿渣与粉煤灰的质量比为4ʒ1,激发剂溶液配合比见表3,水胶比为0.36,附加水质量为水胶比计算所得用水量减去各激发剂中的水含量㊂表3㊀激发剂溶液的配合比Table 3㊀Mix ratio of activator solutionSample No.Alkali content /%Na 2CO 3replacement ratio /%Na 2CO 3content /g NaOH content /g Water glass content /g Additional water content /g J4-0J4-20J4-40J4-60J4-80J4-10040012.0420 3.199.6340 6.387.23609.57 4.828012.77 2.4110015.96077.56133.66J6-0J6-20J6-40J6-60J6-80J6-10060018.0620 4.7914.45409.5710.846014.367.238019.15 3.6110023.940116.34110.48J8-0J8-20J8-40J8-60J8-80J8-10080024.0820 6.3819.274012.7714.456019.159.638025.53 4.8210031.910155.1387.31932㊀资源综合利用硅酸盐通报㊀㊀㊀㊀㊀㊀第43卷1.3㊀试验方法试验前1d 配制激发剂溶液,按表3称取每组试验所需氢氧化钠和碳酸钠与附加水充分搅拌溶解,冷却至室温,再将碱溶液与原水玻璃溶液混合,搅拌至溶液不再分层,用保鲜膜密封静置24h㊂试验时按原材料比例称取粉煤灰㊁矿渣,在搅拌锅中均匀混合后加入激发剂溶液,搅拌4min,其中慢搅2min,中间停歇15s,再快搅2min㊂搅拌结束后参照‘混凝土外加剂匀质性试验方法“(GB /T 8077 2012)㊁‘水泥标准稠度用水量㊁凝结时间㊁安定性检测方法“(GB /T 1346 2011)进行流动度㊁初凝时间和终凝时间测试㊂成型试件尺寸为40mm ˑ40mm ˑ40mm,在标准养护条件下养护至测试龄期,采用YAW-300液压机进行抗压强度测试,加载速率为2400N /s㊂使用德国ZEISS Gemini SEM 300扫描电子显微镜㊁岛津XRD-610衍射仪㊁Thermo Nicolet iS5红外光谱分析仪分析水化产物形貌及物相组成,试件养护至测试龄期后放入无水乙醇终止水化,微观测试前对样品进行烘干㊁研磨处理㊂2㊀结果与讨论2.1㊀流动度图3㊀复合碱激发剂对地聚物胶凝材料流动度的影响Fig.3㊀Effect of composite alkali activator on fluidity of geopolymer cementitious materials 图3为复合碱激发剂对地聚物胶凝材料流动度的影响㊂由图3可见,不同碱掺量下,地聚物净浆流动度均随碳酸钠比例增加呈先增大后减小的趋势,当碳酸钠替代比例为40%时,净浆流动度最大,为175~185mm,当碳酸钠替代比例由80%提升至100%时,净浆流动度显著下降㊂这是由于Na 2CO 3水解产生的CO 2-3与体系中的Ca 2+反应生成CaCO 3沉淀,覆盖在未水化颗粒表面起到润滑作用从而提高流动性㊂然而,当碳酸钠掺量较高时,在反应过程中由于同离子效应,液相中会生成Na 2CO 3㊃10H 2O,导致浆体黏度增大,流动性降低[6]㊂碳酸钠掺量相同时,净浆流动度随碱掺量的增加均呈先增大后减小的趋势㊂当碱掺量为6%时,流动度最大㊂这是因为OH -的极性作用能够加速地聚物中玻璃体Si O 和Al O 的解聚,促进粉煤灰㊁矿渣溶解从而减小颗粒间内摩擦力,提高净浆流动性[13]㊂当碱掺量过高时,较高的溶液浓度以及早期反应中产生的较多凝胶是导致浆体黏度增大㊁流动度降低的主要因素[14]㊂2.2㊀凝结时间保持碱掺量6%不变,碳酸钠掺量对地聚物胶凝材料凝结时间的影响如图4所示㊂地聚物胶凝材料初凝㊁终凝时间均随碳酸钠掺量的增加而延长㊂当碳酸钠替代比例从0%增至80%时,地聚物初凝时间从19min 延长至28min,仅延长了9min,终凝时间从25min 延长至38min,仅延长了13min,碳酸钠的缓凝效果并不明显㊂此时激发剂中氢氧化钠占据主导作用,OH -浓度较高时能加速矿渣溶解,同时抑制CO 2-3参与反应[4]㊂当替代比例提升至100%时,浆体初凝时间㊁终凝时间激增,高达372和420min㊂补充碳酸钠替代比例75%㊁85%㊁90%㊁95%四组配比,以便更清晰地反映碳酸钠掺量对地聚物凝结时间的影响,如图4所示,碳酸钠对地聚物凝结时间的影响依然为连续变化㊂碳酸钠具有缓凝作用主要是因为CO 2-3会优先与体系中的Ca 2+结合生成CaCO 3,阻碍C-(A)-S-H 凝胶的形成,延缓地聚物凝结硬化进程[8,15]㊂同时,大量CO 2-3的存在会降低SiO 4-4参与化学反应的程度,起到缓凝效果[16]㊂保持碳酸钠替代比例40%不变,碱掺量对地聚物胶凝材料凝结时间的影响如图5所示㊂地聚物胶凝材料初凝时间随碱掺量增加线性递增㊂当碱掺量从4%增加至8%时,地聚物胶凝材料初凝时间从10min 增加至35min,当碱掺量为4%和6%时,地聚物胶凝材料终凝时间没有明显差别,均为28min,当碱掺量为8%时,终凝时间延长至43min㊂这是由于随着碱掺量的增加,地聚物中低聚合度前驱体受抑制程度加深,延缓了体系中硅铝酸盐解聚㊁聚合过程[17],这与Hadi 等[18]㊁王玲玲等[19]研究结果一致㊂第3期蒋明屾等:碳酸钠㊁氢氧化钠与水玻璃复合激发对地聚物胶凝材料性能的影响933㊀图4㊀碳酸钠掺量对地聚物胶凝材料凝结时间的影响Fig.4㊀Effect of sodium carbonate content on setting time of geopolymer cementitiousmaterials 图5㊀碱掺量对地聚物胶凝材料凝结时间的影响Fig.5㊀Effect of alkali content on setting time of geopolymer cementitious materials2.3㊀抗压强度地聚物胶凝材料抗压强度随碳酸钠替代比例增加的变化趋势如图6所示㊂由图6可知,随着碳酸钠掺量增加,不同碱掺量地聚物胶凝材料的3㊁7d 抗压强度均呈下降趋势,当碱掺量为8%㊁碳酸钠替代比例0%时,3㊁7d 抗压强度达到最大值,分别为66.2和76.3MPa㊂随着碳酸钠掺量增加,地聚物胶凝材料均呈先升高后降低的趋势,当碳酸钠掺量为4%时,28d 抗压强度在碳酸钠替代比例为20%时达到最大值,为85.2MPa;当碳酸钠掺量为6%与8%时,28d 抗压强度在碳酸钠替代比例为40%时达到最大值,分别为94.4和93.9MPa㊂图6㊀不同碱掺量下碳酸钠替代比例对地聚物胶凝材料抗压强度的影响Fig.6㊀Effect of sodium carbonate replacement ratio on compressive strength of geopolymer cementitious materials with different alkalicontent 图7㊀地聚物胶凝材料3㊁28d 的抗压强度比Fig.7㊀Compressive strength ratio 3and 28d ofgeopolymer cementitious materials 地聚物胶凝材料3㊁28d 强度比如图7所示㊂当碳酸钠替代比例为0%时,即使用氢氧化钠与水玻璃复合激发时,地聚物胶凝材料早期强度增长迅速,后期强度增长缓慢,3d 抗压强度可以达到28d 抗压强度的63.6%~80.1%㊂当碱掺量为8%时,28d 抗压强度82.6MPa 相比于3d 抗压强度66.2MPa,仅提升了24.8%㊂当碳酸钠替代比例100%时,即用碳酸钠与水玻璃复合激发时,3d 抗压强度为28d 抗压强度的44.9%~60.1%㊂对比可知当体系中引入碳酸钠时,地聚物早期强度发展缓慢,后期强度发展相对迅速㊂当碱掺量为4%时,3d 抗压强度为28.1MPa,28d 抗压强度为62.7MPa,抗压强度增长率高达123.1%㊂934㊀资源综合利用硅酸盐通报㊀㊀㊀㊀㊀㊀第43卷碱浓度对地聚物胶凝材料早期强度发展起到决定作用,加入碳酸钠会使体系中pH值降低,削弱激发剂对地聚物中玻璃体结构的解聚效果,延长水化进程,导致强度发展缓慢㊂同时,较长的凝结硬化时间有利于C-A-S-H的形成,促使强度随龄期进一步发展[9]㊂当碳酸钠替代比例较高时,反应会存在一段时间的休眠期[20],早期水化产物大多为不同形态的碳酸钙,如方解石和文石以及少量的单斜钠钙石,CO2-3浓度成为控制反应进程的主要因素㊂随着水化进程发展,单斜钠钙石积累和水滑石形成会不断消耗CO2-3,导致体系中CO2-3浓度下降,逐渐释放Ca2+与[SiO4]4-结合形成C-(A)-S-H凝胶[21],促进硬化体强度发展㊂不同碱掺量时,28d强度最大值均出现在三种激发剂复合作用的情况下,这可能是因为在氢氧化钠-水玻璃激发体系中加入适量的碳酸钠参与孔溶液化学反应有助于优化水泥石结构,减小孔隙从而提升强度㊂2.4㊀物相组成图8(a)㊁(b)为地聚物胶凝材料养护水化3㊁28d后的FTIR谱㊂使用不同激发剂时,地聚物胶凝材料水化产物具有较高的相似度㊂1414~1488cm-1处的双峰和870cm-1附近的吸收带是由不同水化产物中O C O(CO2-3)非对称拉伸和平面外弯曲振动引起的[22],3d时随碳酸钠含量增大,特征峰强度显著提高,养护㊁研磨过程中样品的碳化与风化导致J6-0中也存在该特征峰㊂980~1020cm-1附近的吸收峰对应C-(A)-S-H中SiO4四面体的Si O伸缩振动㊂水玻璃或NaOH激发的地聚物C-(A)-S-H凝胶Si O Si伸缩带一般在950~1000cm-1,随着碳酸钠含量提高,该特征峰向高波数移动,表明C-(A)-S-H中Si含量相对较高[23],水化产物聚合度增大㊂450cm-1处的吸收峰归属于Si O Si的平面弯曲振动,这与体系中无定形铝硅酸盐沸石结构有关[24-25]㊂1650cm-1附近的微弱峰包与硬化体中化学结合水H O H弯曲振动有关㊂图8㊀地聚物胶凝材料水化3㊁28d的FTIR谱Fig.8㊀FTIR spectra of geopolymer cementitious materials hydration for3and28d 图9(a)㊁(b)为地聚物胶凝材料水化3㊁28d后的XRD谱㊂XRD谱整体呈弥散状驼峰,表明地聚物胶凝材料的水化产物多为无定形凝胶,结晶性较差㊂反应早期矿渣溶解释放的Ca2+优先与孔隙溶液中的CO2-3结合,少量Ca2+与[SiO4]4-结合,主要水化产物为CaCO3㊁C-(A)-S-H凝胶㊂随着碳酸钠含量增加,CaCO3衍射峰强度明显提高,单斜钠长石(Na2Ca(CO3)2㊃5H2O)与钠沸石(Na12Al12Si12O48-n H2O)衍射峰开始出现㊂CO2-3对Ca2+的消耗促使钠沸石中Si和Al达到饱和[8]㊂水化28d时,可以明显观察到单斜钠长石与钠沸石衍射峰强度降低,水滑石(Mg6Al2(OH)16CO3㊃4H2O)衍射峰开始出现㊂一些学者[8,26]认为,单斜钠长石与钠沸石在水化产物中的存在形式并不稳定,随龄期发展会进一步向C-(A)-S-H㊁水滑石㊁钙沸石(CaAl2Si7O18㊃n H2O)等稳定产物进行转化,对比图9(a)㊁(b)可证明反应前㊁后期产物发生转变㊂此外,石英与莫来石的衍射峰来自体系中未水化的粉煤灰㊂2.5㊀微观形貌使用J6-0㊁J6-40㊁J6-100激发时,地聚物胶凝材料3㊁28d的SEM照片如图10所示㊂使用不同激发剂激发水化3d后,体系中均存在未反应的粉煤灰颗粒,随着激发剂中碳酸钠含量增多,早期水化产物㊁硬化体结构逐渐由致密变得松散,28d水化产物整体呈块状㊂仅使用氢氧化钠与水玻璃复合激发时,3d出现较为致㊀第3期蒋明屾等:碳酸钠㊁氢氧化钠与水玻璃复合激发对地聚物胶凝材料性能的影响935密的块状凝胶结构,28d水化结构与3d相差不大,证明水化反应主要发生在早期㊂当使用碳酸钠与水玻璃复合激发时,早期水化产物极为疏松,甚至可以观察到未反应的矿渣,所以此时地聚物胶凝材料强度较低㊂水化28d后,在硬化体表面可以观察到不规则晶体,这与詹疆淮等[27]观察到的三维无定形类沸石结构铝硅酸盐凝胶类似,产物结构相对致密㊂三种激发剂复合作用时,28d硬化体结构非常致密,微裂缝数量减少,裂缝宽度明显减小,从微观层面进一步解释了该组地聚物胶凝材料抗压强度更高的原因㊂图9㊀地聚物胶凝材料3㊁28d的XRD谱Fig.9㊀XRD patterns of geopolymer cementitious materials for3and28d图10㊀地聚物胶凝材料3㊁28d的SEM照片Fig.10㊀SEM images of geopolymer cementitious materials for3and28d936㊀资源综合利用硅酸盐通报㊀㊀㊀㊀㊀㊀第43卷3㊀结㊀论1)地聚物胶凝材料净浆流动度随碱掺量㊁碳酸钠含量增加均呈先增大后减小的趋势㊂当碱掺量为6%㊁碳酸钠替代比例为40%时,净浆流动度达到最大值,为185mm㊂2)地聚物胶凝材料凝结时间随碱掺量增加而增大㊂当碳酸钠替代比例为0%~80%时,碳酸钠含量对地聚物胶凝材料凝结时间的影响并不显著㊂当替代比例为80%~100%时,地聚物胶凝材料凝结时间随碳酸钠含量增加显著提高㊂当替代比例为100%时,地聚物胶凝材料初凝时间㊁终凝时间可达372和420min㊂3)地聚物胶凝材料3㊁7d抗压强度均随碱掺量增加而提高,随碳酸钠含量增加而降低㊂28d抗压强度相差不大,碱掺量为6%与8%时略大于碱掺量为4%时,且随着碳酸钠含量增加先提高后降低㊂当碱掺量为6%㊁碳酸钠替代比例为40%时,28d抗压强度达到最大值,为94.4MPa㊂4)不同碱组分激发地聚物胶凝材料水化产物相似㊂氢氧化钠复合水玻璃作为激发剂时,不同龄期水化产物均以无定形铝硅酸盐C-(A)-S-H凝胶为主㊂碳酸钠复合水玻璃作为激发剂时,早期水化产物中含有大量碳酸钙并出现单斜钠长石与钠沸石,后期水化产物中单斜钠长石与钠沸石含量降低,出现水滑石㊁钙沸石以及C-(A)-S-H凝胶㊂参考文献[1]㊀SCRIVENER K L,KIRKPATRICK R J.Innovation in use and research on cementitious material[J].Cement and Concrete Research,2008,38(2):128-136.[2]㊀黄㊀华,郭梦雪,张㊀伟,等.粉煤灰-矿渣基地聚物混凝土力学性能与微观结构[J].哈尔滨工业大学学报,2022,54(3):74-84.HUANG H,GUO M X,ZHANG W,et al.Mechanical property and microstructure of geopolymer concrete based on fly ash and slag[J].Journal of Harbin 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材料low k dielectric materials

We all want our computers to work faster. The most direct way to increase the speed of an IC is to pack in more transistors that are smaller and faster. For the last two decades, device feature size has decreased from 1 µm down to 90 nm, increasing the working frequency of microprocessors from 66 MHz to 4 GHz.However, not all IC components work faster when decreased in size. While continuous shrinking makes transistors faster, it makes interconnections between transistors work slower (Fig. 1).Why is this so? The answer is interconnection delay. Any interconnection can be represented (Fig. 2)as a chain ofresistors (wires) and capacitors (insulating dielectric between wires). A good figure of merit to characterize interconnects is resistance-capacitance (RC), which is a unit of time. A signal propagating through the interconnection experiences RC delay. Shrinking the cross-section of a wire increases its resistance and bringing wires closer together increases capacitance between the wires. As a result, RC delay increases as device size decreases.It is predicted that RC delay will soon exceed transistor speed, becoming a serious limitation to performanceimprovement. Since scaling down dimensions works against RC delay, the only way to bring down resistance andcapacitance is to use other metals (with lower resistivity) and dielectrics (with lower dielectric constant) instead of the conventional Al and SiO 2, respectively.The replacement of Al with Cu (36% decrease inresistivity) was the first step taken to address RC delay. The best conductor, Ag, has a resistivity only 6% lower than thatby D. Shamiryan 1, T. Abell 2, F. Iacopi 1,3and K. Maex 1,3Low-kdielectric materials1IMEC,Kapeldreef 75,3001 Leuven, Belgium2Intel affiliate researcher at IMEC3Also at Katholieke Universiteit Leuven E-mail: maex@imec.beJanuary 200434ISSN:1369 7021 © Elsevier Ltd 2004Performance improvements in microelectronic integrated circuits (ICs) over the past few decades have, for the most part, been achieved by increasing transistor speed, reducing transistor size, and packing more transistors onto a single chip. Smallertransistors work faster, so ICs have become faster and more complex. An emerging factor that may disrupt this trend is the slowing speed of signal propagation within the chip. Signal delays, caused by theinterconnection wiring, increase with each generation of scaling and may soon limit the overall performance of the integrated system.REVIEW FEATUREJanuary 200435of Cu. Considerable effort has been necessary to successfully integrate Cu into IC manufacturing.Changing materials in IC processing requires intensiveresearch, development, and integration engineering. Replacing SiO 2has not been a straightforward process and is a major undertaking in materials design and engineering. In principle,any material with a dielectric constant k lower than 4.2 is of interest (so called low-k dielectrics), but the k value is only one of many required properties. In this paper, we will briefly review ways of reducing k , survey the available low-k materials, and identify the problems associated with their integration in microelectronic circuits. A more detailed treatment is given elsewhere 1.How to reduce k -valueDielectric constant k (also called relative permittivity εr ) is the ratio of the permittivity of a substance to that of free space. A material containing polar components, which are represented as electric dipoles (e.g. polar chemical bonds),has an increased dielectric constant (Fig. 3). The dipoles align with an external electric field, adding the electric field ofevery dipole to the external field. As a result, a capacitor with a dielectric medium of higher k will hold more electric charge at the same applied voltage or, in other words, itscapacitance will be higher. The dipole formation is a result of electronic polarization (displacement of electrons), distortion polarization (displacement of ions), or orientationpolarization (displacement of molecules) in an alternating electric field. These phenomena have characteristicdependencies on the frequency of the alternating electric field, giving rise to a change in the real and imaginary part of the dielectric constant between the microwave, ultraviolet,and optical frequency range.Fig. 2 Schematic view of Cu lines embedded in dielectric. Interline capacitance must be reduced in order to bring the signal propagation delay down. The photo shows a cross-section of interconnections for 90 nm technology. (Courtesy of Intel.)Fig. 1 As transistor size decreases, operation speed increases. However, the operationspeed of wiring decreases because of the delay in signal propagation through interconnect lines. At some point, the interconnects become slower than the transistors and limit the performance of the electronicdevice. Reducing interconnect delay is of key importance.Fig. 3 Schematic view of a capacitor. The same voltage will produce a higher electric field inside a capacitor with electric dipoles (e.g. polar bonds like Si-O) between the electrodes compared to a capacitor with vacuum between the electrodes (not shown). The ratio of these fields is called the relative dielectric constant k. The capacitance can be reduced by decreasing the k value of the dielectric between the electrodes.There are two possible ways of reducing k: decreasing dipole strength or the number of dipoles (Fig. 4). This means using materials with chemical bonds of lower polarizability than Si-O or lower density materials. The two methods can be combined to achieve even lower k values. The IC industry has already moved to certain low-k materials, where some silica Si-O bonds have been replaced with less polar Si-F orSi-C bonds. A more fundamental reduction can be achieved by using virtually all nonpolar bonds, such as C-C or C-H, for example, in materials like organic polymers.The density of a material can be decreased by increasing the free volume through rearranging the material structure or introducing porosity. Porosity can be constitutive or subtractive. Constitutive porosity refers to the self-organization of a material. After manufacturing, such a material is porous without any additional treatment. Constitutive porosity is relatively low (usually less than 15%) and pore sizes are ~ 1 nm in diameter. According to International Union of Pure and Applied Chemistry (IUPAC) classification2, pores less than 2 nm are denoted ‘micropores’.Subtractive porosity involves selective removal of part of the material. This can be achieved via an artificially added ingredient (e.g. a thermally degradable substance called a‘porogen’, which is removed by an anneal to leave behind pores) or by selective etching (e.g. Si-O bonds in SiOCH materials removed by HF). Subtractive porosity can be as high as 90% and pore sizes vary from 2 nm to tens of nanometers (pores larger than 2 nm are denoted‘mesopores’). A mesoporous organic polymer can combine all three approaches: low polarizability, inherent free volume (constitutive porosity), and use of porogens (subtractive porosity). The ultimate case would be the use of air as a dielectric with the lowest possible k of 1, so called ‘air gaps’.Classification of low-k materialsThere are many available low-k materials and they can be classified into groups (Fig. 5). Low-k materials can be viewed as Si-(or, more precisely, Si-O)-containing andnon-Si-containing. Si-containing materials, in turn, can be divided into two subgroups: silica-based and silsesquioxane (SSQ)-based. The principal difference between the latter two groups is the structure of their elementary units.Silica has a tetrahedral elementary unit (Fig. 6). To reduce the k value of silica, some oxygen atoms are replaced with F, C, or CH3. The addition of CH3not only introduces less polar bonds, but also creates additional free volume. Such silicon oxycarbides (SiOCH) are constitutively porous. Historically, the first low-k materials were silica-based (F- or C-doped SiO2), since SiO2was well understood for IC fabrication processing.In the SSQ elementary unit, Si and O atoms are arranged in a form of cube (Fig. 7). This creates free volume in the center of the cube, decreasing the material’s density and, therefore, its k value. The cubes can be connected to each other through oxygen atoms, while some cube corners are terminated by hydrogen. Such materials are called hydrogen-SSQ (HSSQ). If methyl groups are present, the cubes can be connected by -CH2-, while some cube corners are terminated by CH3. This is termed methyl-SSQ (MSSQ). SSQ cubes are metastable and tend to break down to silica tetrahedra,REVIEW FEATUREJanuary 200436Fig. 5 A simplified classification scheme of low-k dielectrics. Fig. 4 Possibilities for reducing the k value of dielectrics.REVIEW FEATUREespecially at elevated temperatures. As a result, SSQ-based materials realistically represent a mixture of SSQ cubes and silica tetrahedra. Both silica- and SSQ-based materials usually have k values between three and four, which can be decreased further by porosity.Non-Si based materials are mostly organic polymers. Their main advantage is low polarizability, which results in k values as low as two without porosity. The main disadvantage of polymers is their poor compatibility with existing semiconductor processing (e.g. low thermal and mechanical stability). There are other low-k materials available(e.g. amorphous carbon3or zeolites4), but they have not received as much attention as the three groups described.In IC manufacturing, low-k materials are used as thin filmsof around 500 nm. There are two main methods ofdeposition: spin coating and chemical vapor deposition (CVD). Spin-coated films can be constitutively as well as subtractively porous. Low temperatures allow theintroduction of thermally degradable porogens into the mixture, which can be removed by a thermal anneal step. The anneal also induces chemical cross-linking, producing a rigidfilm structure regardless of subtractive or constitutiveporosity. Typically, CVD films are constitutively porous. The introduction of a porogen is possible, but it is complicated bythe fact that deposition usually occurs at elevatedtemperatures (~300°C) and is often enhanced by plasma. Integration of low-k materialsDeposition of a uniform, thin, and porous low-k film is onlythe first of many challenges. The real challenge is integrationof the film into IC manufacturing processes (Fig. 8).Compared to SiO2, low-k materials are mechanically weak, thermally unstable, poorly compatible with other materials,able to absorb chemicals, etc. Integration of low-k materialsis comparable to building a fire- and waterproof wall out of sponge rather than concrete because low weight is a concern. There are five general requirements for a low-k material to be successfully integrated: hydrophobicity; mechanical stability;January 200437Fig. 6 A schematic representation (not to scale) of a tetrahedral silica unit (a) and the same unit of SiOCH material (b). Replacing an oxygen atom by a CH3group reduces the k value by introducing a less polar bond and by creating additional free volume (constitutive porosity).Fig. 7 A schematic representation (not to scale) of a silsesquioxane (SSQ) unit. The SSQ may contain hydrogen (HSSQ) or methyl groups (MSSQ). The cubes are metastable and tend to decompose to silica tetrahedra at elevated temperatures. The cubes are connected to each other through an oxygen atom (HSSQ) or a -CH2- radical (MSSQ).Fig. 8 Relative dielectric constant (k value) as a function of porosity for differentdielectrics. The difference between materials diminishes with increasing porosity.State-of-the-art integration of low-k materials in semiconductor processing is indicatedby the shaded area.thermal stability; chemical and physical stability under processing conditions; and compatibility with other materials. There is also the very important challenge for all functional materials: reliability in the user environment. Hydrophobicity A low-k material must be hydrophobic. Water has extremely polar O-H bonds and a k value close to 80. Even a small amount of absorbed water significantly increases the total k value. As water is abundant in air (typical relative humidity is 40-60%), a low-k material should be as hydrophobic as possible to prevent deterioration of its k value. This is especially important for porous materials, as they have a large surface area per unit volume where water could potentially be adsorbed. Hydrophobicity is usually achieved by the introduction of Si-H or Si-CH3 bonds. Oxygen-free organic polymers are generally hydrophobic.Mechanical stability The need for mechanical stability is primarily a consequence of the introduction of Cu as the electrical conductor in the wiring of ICs. When Al was used, the substrate was coated with Al, which was then patterned using photolithography and plasma etching. Unnecessary Alwas etched away, leaving behind the wires. The space between the freestanding wires was then filled with dielectric (SiO2). Unfortunately, Cu does not form volatile compounds with reactive gases and, therefore, plasma etching cannot be used. As a result, the process scheme is reversed. First, a substrate is coated with a dielectric layer and trenches are formed by plasma etching where Cu wires should be present.A Cu layer is then deposited by electroplating to fill the trenches and excess Cu is polished away. This technology is known as ‘damascene’ because Cu lines embedded in dielectric resemble damascene decoration. In the last step of the process, the dielectric must withstand mechanical stresses during the Cu removal polish. Low-k dielectric materials must also be able to survive stresses induced by the mismatch of thermal expansion coefficients or mechanical stresses during the packaging process, when fully processed circuits are connected to the outside world.Mechanical properties quickly deteriorate as porosity increases. The Young’s modulus of bulk SiO2decreases from 76 GPa to several GPa for materials with 50% porosity. As the Young’s modulus of a low-k material drops below 10 GPa, integration becomes far more challenging (Fig. 9). Therefore, the porosity of a low-k film should be as low as possible to provide sufficient mechanical stability.Thermal stability A low-k material must withstand the temperatures used for interconnect manufacturing. The temperatures can be as high as 400-450°C. This is an issue for some organic polymers, as they begin to decompose at lower temperatures, implying severe restrictions on thermal processing and reducing the choice of polymers. In SSQ-based materials, elevated temperatures cause the conversion of SSQ cubes into silica tetrahedra, increasing the k value of the material.Chemical and physical stability A low-k material must withstand other processing steps, especially etching and cleaning. For example, oxygen plasma used during patterning (trench etching) or cleaning of low-k material can break Si-H, Si-C, and Si-CH3bonds, replacing them with Si-O. This increases the k value by introducing bonds of higher polarity and reduces hydrophobicity, which makes the material prone to water adsorption. The damaging effect is more pronounced for highly porous materials. It should be noted, though, that these processes can be tuned to reduce their effect onlow-k materials.Compatibility with other materials This is a broader requirement and more difficult to specify. The three major concerns are the coefficient of thermal expansion (CTE), barrier deposition, and adhesion.REVIEW FEATUREJanuary 200438Fig. 9 Mechanical properties (Young’s modulus) of low-k films as a function of porosity. As film porosity increases, the Young’s modulus drops, making integration of the film difficult because of mechanical instabilities during processing. The photos illustrate some of the mechanical issues encountered: creep, delamination, and cohesive failure.REVIEW FEATUREA low-k material must be compatible with Cu in termsof CTE as described above. This is especially an issue for organic polymers, which can have significant CTE mismatches with Cu.A low-k film must also be compatible with the diffusion barrier, which is needed to prevent the penetration of Cu, known for its high diffusivity. Cu readily degrades the dielectric properties of the insulator, increasing leakage currents and decreasing breakdown voltage. As a result, the reliability of devices significantly decreases, making their lifetimes unacceptably short. Cu diffusivity drastically increases with dielectric porosity. The barrier must stop Cu diffusion with zero tolerance. It must be thin (nanometer scale) and fully dense (contain no pinholes). Covering a porous material with such a barrier is nontrivial (Fig. 10). If the material is highly porous with large pores connected to each other, the barrier may have to be unacceptably thick in order to bridge all the exposed pores. It should be noted that the barrier itself should not penetrate into the porous material, which is a possibility with some deposition techniques. Deposition of a rigorous barrier tends to beeasiest when pores are small and porosity is low.Good adhesion between a low-k material and the barrier is another requirement. Otherwise, the barrier can delaminate because of the mechanical stresses induced by polishing or thermal cycling. Adhesion can also become more of an issueas the porosity of low-k materials increases.Reliability There are many issues associated with thereliability of low-k materials. These materials will be implemented into circuits and systems and their propertieshave to persist in typical ‘user’ environments for a sufficiently long time. Thermal conductivity strongly decreases with porosity. Consequently, heat dissipation in the wires leads to increased electromigration of Cu5. In addition, because theCu wire is no longer firmly restrained in a rigid dielectric,failure by hillock formation (extrusion of Cu through the surrounding dielectric) is more likely to occur. Furthermore,the thermal conduction mechanism in these newly developed materials has not been studied sufficiently to assure the long lifetime of the final circuit.ConclusionsReduction of the dielectric constant of a material can be accomplished by selecting chemical bonds with low polarizability and introducing porosity. Integration of such materials into microelectronic circuits, however, poses anumber of challenges, as the materials must meet strict requirements in terms of properties and reliability.The introduction of low-k materials in microelectronics research and development is a good example of howindustrial needs drive new fundamental and applied research topics in science. Examples include pore structure characterization, deposition of thin films on poroussubstrates, mechanical properties of porous films, and conduction mechanisms in these materials.The substantial efforts made by materials and ICresearchers to integrate the low-k films and continuehistorical device performance improvements have contributedto, and are still leading to, innovative fundamental andapplied science. MTJanuary 200439REFERENCES1.Maex, K., et al., J. Appl. Phys.(2003) 93 (11), 87932.Rouquerol, J., et al., Pure Appl. Chem. (1994) 66, 17393.Grill, A., Thin Solid Films (1999) 355-356, 1894.Wang, Z. B., et al., Adv. Mater.(2001) 13 (10), 7465.Lee, K.-D., et al., Appl. Phys. Lett.(2003) 82 (13), 2032Fig. 10 A schematic representation of a thin film deposited on a porous material with (a) separated mesopores connected by microchannels and (b) interconnected mesopores. As porosity increases, the mesopore connections make the deposition of a continuous film more difficult. The photos show examples of barrier integrity tests by HF dip. A fully continuous barrier (c) prevents HF from attacking the underlying dielectric, but discontinuities or ‘pinholes’ in the barrier allows HF to attack the dielectric (d).。

水泥行业脱硝催化剂的失活及资源化利用

水泥行业脱硝催化剂的失活及资源化利用郑鹏1，2 马国强1，2 何发泉1 李年华2 吴易昊1，2（1.国能龙源环保有限公司；2.国能龙源内蒙古环保有限公司）摘要：随着水泥行业超低排放改造的深入推进，脱硝催化剂得到了更广泛的应用，但受高尘、高碱（碱土）金属、高重金属等恶劣工况影响，水泥行业脱硝催化剂的失活速率远快于火电行业。

本文系统论述了水泥行业脱硝催化剂的失活机理，并对退役脱硝催化剂资源化利用的两条技术路线——再生以及回收利用的最新研究及产业化成果进行了总结。

关键词：水泥，脱硝催化剂，失活，再生，回收Deactivation and Resource Utilization of SCR Catalystsin Cement IndustryZHENG Peng1, 2 MA Guo-qiang1, 2 HE Fa-quan1 LI Nian-hua2 WU Yi-hao1, 2（1. China Energy Longyuan Environmental Protection Co., Ltd.;2. China Energy Longyuan (Inner Mongolia) Environmental Protection Co., Ltd.）Abstract:With the deepening of “ultra-low emissions” transformation in the cement industry, SCR catalysts have been widely used. However, due to the severe operation conditions such as high dust, high alkali (alkaline earth) metals, and high heavy metals, the deactivation rate of SCR catalysts in the cement industry is much faster than that in the power industry. This paper discusses the deactivation mechanism of SCR catalysts in the cement industry, and summarizes the latest research and industrialization achievements of two technical approaches, i.e. the regeneration and recycling of deactivated SCR catalysts .Keywords: cement, SCR catalyst, deactivation, regeneration, recycling基金项目：作者简介：本文受国电科技环保集团有限责任公司科技项目（项目编号：KH-2023-04）资助。

锆合金的研发历史、现状及发展趋势

㊀第41卷㊀第5期2022年5月中国材料进展MATERIALS CHINAVol.41㊀No.5May 2022收稿日期:2021-12-15㊀㊀修回日期:2022-03-22基金项目:国家自然科学基金优青项目(51922082)第一作者:贾豫婕,女,1997年生,博士研究生通讯作者:韩卫忠,男,1981年生,教授,博士生导师,Email:wzhanxjtu@DOI :10.7502/j.issn.1674-3962.202112010锆合金的研发历史㊁现状及发展趋势贾豫婕,林希衡,邹小伟,韩卫忠(西安交通大学金属材料强度国家重点实验室,陕西西安710016)摘㊀要:锆合金作为一种重要的战略材料,被誉为原子能时代的第一金属 ,由于其低中子吸收率㊁抗腐蚀㊁耐高温等优点,被广泛用作核反应堆关键结构材料㊂我国锆合金基础研究及工业化发展起步较晚,锆合金种类较少,因此,锆合金的研发受到了学术界及工业界的广泛重视㊂回顾了核用锆合金研发的历史进程㊁应用现状及未来发展趋势,阐明了锆合金基础研究和开发应用的重要性,简要介绍了新兴的高性能锆合金,包括医用锆合金㊁耐腐蚀锆合金㊁高强高韧锆合金和锆基非晶合金㊂随着核反应堆的升级换代和非核用应用需求的多样化,发展新型锆合金㊁拓展锆合金的应用范围,是锆合金未来研发的着眼点㊂关键词:锆合金;包壳;强韧化;耐蚀性;抗辐照性中图分类号:TG146.4+14;TB31㊀㊀文献标识码:A㊀㊀文章编号:1674-3962(2022)05-0354-17引用格式:贾豫婕,林希衡,邹小伟,等.锆合金的研发历史㊁现状及发展趋势[J].中国材料进展,2022,41(5):354-370.JIA Y J,LIN X H,ZOU X W,et al .Research &Development History,Status and Prospect of Zirconium Alloys[J].Materials China,2022,41(5):354-370.Research &Development History ,Status andProspect of Zirconium AlloysJIA Yujie,LIN Xiheng,ZOU Xiaowei,HAN Weizhong(State Key Laboratory for Mechanical Behavior of Materials,Xi a n Jiaotong University,Xi a n 710016,China)Abstract :Zirconium alloys,as an important strategic material,also widely known as the first metal in the atomic-energyage ,are widely used in nuclear reactors as key structural components because of their small thermal neutron capture cross-section,excellent corrosion resistance and high-temperature mechanical properties.The fundamental research and industrial-ization of zirconium alloy in China is later than that of the developed countries.As a result,our zirconium industries have less variants of products,which attract broad attentions from the academic communities and industry sectors.In this review,we retrospect the development history,application status and future trends of nuclear-related zirconium alloys,and empha-size the importance of accelerating fundamental research and developing new zirconium alloys.The design and development of advanced high-performance zirconium alloys are also briefly introduced,including medical-used zirconium alloys,corro-sion-resistant zirconium alloys,high strength-high toughness zirconium alloys and zirconium-based amorphous alloys.With the requirements of further upgrading of nuclear reactors and the diverse applications,the development of new zirconium al-loys and the broadening of their applications are key points in future research &development of advanced zirconium alloys.Key words :zirconium alloy;fuel cladding;strength-ductility;corrosion resistance;irradiation resistance1㊀前㊀言锆元素的地壳丰度约为1.30ˑ10-4,处于第18位㊂然而,锆矿石全球储量分布不均,如图1a 所示,供需市场严重错位[1]㊂锆的熔点为1852ħ,具有低毒㊁耐腐蚀㊁热中子吸收截面小㊁高温力学性能优良㊁与人体相容性好等优点;其化合物如氧化锆㊁氯氧化锆等具有独特的化学和物理性能㊂因此,锆及锆制品被广泛应用于核工业㊁化学工业㊁陶瓷工业㊁耐火材料工业㊁铸造业㊁航空航天㊁医疗行业等㊂目前,我国锆产业的生产和发展主要有2个特点:一是锆矿石严重依赖进口(图1a);二是主要消费品集中在陶瓷等领域,初级产品占比高㊁产能过剩,整体产业污染高㊁效益低㊁高端产品占比少㊁All Rights Reserved.㊀第5期贾豫婕等:锆合金的研发历史㊁现状及发展趋势自主化程度低[2-4](图1b)㊂因此,亟需合理规划和布局锆行业的发展,提高锆相关产品的技术含量和附加值,打破锆合金高端市场的国际垄断,在国内建立完整高效的锆合金供应链,对整个锆合金行业进行深入思考和规划㊂图1㊀锆资源分布及生产分析:(a)全球锆矿资源分布[1],(b)国内锆合金产业结构分析及预测[2-4]Fig.1㊀Zr reserves and production:(a)world Zr reserves [1],(b)analysis and forecast of China Zr industry [2-4]2㊀核用锆合金的研发现状2.1㊀国外锆合金研发历程核燃料包壳材料选择的多重设计约束包括抗蠕变性能㊁强度㊁韧性㊁抗中子辐照㊁热中子吸收截面㊁高温性能㊁化学兼容性等各种综合性能的限制[5]㊂锆合金在高温材料中具有较低的热中子吸收截面和较为优良的抗辐照能力,自20世纪50年代开始作为核反应堆中重要的结构材料延用至今㊂美国㊁俄罗斯㊁法国及德国等国家自20世纪50年代起先后研发出一系列锆合金㊂受当时的冶炼条件限制,高纯锆在冶炼及加工过程中会不可避免地引入Ti,C,Al,N,Si 等有害杂质,降低了合金的耐腐蚀性能㊂Sn 作为α相稳定元素,能吸收合金中有害杂质[6]㊂因此,美国于1951年研发出了Zr-2.5Sn 合金,即Zr-1合金[7-9]㊂并在Zr-1合金基础上调整合金成分研制出了Zr-2合金(Zr-1.7Sn-0.2Fe-0.1Cr-0.05Ni),但Ni 元素的加入导致Zr-2合金吸氢量增加㊂于是,在Zr-2合金基础上去掉Ni 元素,增加Fe 元素,研制出了Zr-4合金[10]㊂锆合金中较高含量的Sn 不利于进一步提高合金的耐腐蚀性能,之后,随着冶炼技术的发展,通过将Zr-4合金中的Sn 含量控制在较低水平,并通过增加Fe 和Cr 的含量,改进型Zr-4合金得到了发展㊂此外,不同于美国侧重于研发Zr-Sn 系合金,依据Nb 元素较小的热中子吸收截面和强化合金的作用,前苏联发展了E110等Zr-Nb 系合金[11],加拿大开发了Zr-2.5Nb 合金用作CANDU 重水反应堆的压力管材料[12]㊂随着各国不断提高燃料能耗㊁降低循环成本,改进型Zr-4合金已不能满足50GWd /tU 以上的高燃耗要求[13],各种新型高性能锆合金相继被研发并且部分合金已投入生产,如法国的M5合金[14]㊁美国西屋公司的Zirlo 合金[15]㊁前苏联的E635合金[16]㊁日本的NDA 合金[6]㊁韩国的HA-NA 合金[6]等㊂2.2㊀我国锆合金研发历程面对国外长期的技术封锁及国家核工业发展的急需,我国从20世纪60年代初开始了锆合金的研究及工业化生产,期间成功制取了原子能级海绵锆,建设了西北锆管有限责任公司等具有先进水平㊁与中国大型核电站配套发展的现代化企业,生产制造的国产Zr-4合金完全满足工程要求㊂自20世纪90年代初开始,我国研制了以N18(NZ2)和N36(NZ8)合金为代表的具有自主知识产权的第三代锆合金[17,18]㊂21世纪初开始,一批性能优异的CZ 系列㊁SZA 系列锆合金先后启动研发㊂国内外几种典型核用锆合金的成分对比如表1所示[19]㊂作为核工业的重要材料,核级锆材的国产化生产至关重要㊂将国内外重要的锆合金牌号及其相应的研发年份汇总至图2中[6-17],可以发现我国目前已经具备了各类核级锆材的供应能力,建立了较为完整的自主化核级锆材产业体系,但产能较低㊁自主化水平较弱㊂据中国核能行业协会‘2021年核电行业述评及2022年展望“可知,截至2021年12月底,我国大陆地区商运核电机组53台,总装机容量为5463.695万千瓦;在建核电机组16台,总容量是1750.779万千瓦㊂因此,我国的核电产业每年所需锆材约为1071.6~1268.4t,海绵锆约为2143.2~2536.8t [20]㊂目前国核宝钛锆业㊁中核晶环锆业㊁东方锆业的海绵锆年产能分别约为1500,500和150t,总体产能低于每年海绵锆的需求量㊂总体来看,通过加强锆矿石进口海外布局,推动核用锆合金自主化,提高锆合金企业研发能力和生产效益,是突破我国核工业关键材料卡脖子问题㊁确保我国能源安全的关键一步㊂553All Rights Reserved.中国材料进展第41卷表1㊀几种典型核用锆合金的成分[19]Table 1㊀Composition of several typical nuclear Zr alloys [19]Alloy Chemical compositions /wt%Sn Nb FeCrNi Cu Country Zr-2 1.5 0.150.10.05 USA Zr-41.50.220.1 USAE110 1.0USSR E1252.5Canada Zr-2.5Nb-0.5Cu2.5 0.5Canada Zirlo1.01.00.1USAE635 1.20 1.00.4USSR N18(NZ2)1.00.30.30.1ChinaN36(NZ8) 1.01.00.3China图2㊀国内外锆合金研发历程[6-17]Fig.2㊀Research history of Zr alloys [6-17]2.3㊀核用锆材发展趋势锆合金的研发周期长㊁服役要求高,从研发到批量化生产需要经过大量的性能测试和工序调整(见图3),因此,近20年内核反应堆服役的锆合金种类及应用结构部件近乎不变[21-23],目前核反应堆常用锆合金应用情况如表2所示[21-25]㊂但随着三代核反应堆的逐渐发展及应用,在保证核反应堆安全㊁高效㊁经济的前提下,其燃耗㊁服役寿命及可用性需求不断提升[24],如华龙一号平均燃耗达到45000MWd /tU 以上㊁CAP1400的目标燃耗为60000MWd /tU㊁锆合金的换料周期从12个月延长至18个月及以上,这些要求使得各国密切关注锆合金服役性能的提升㊂其中,拟采取的主要措施为多元合金化和改进加工工艺[25]㊂同时,在现有锆合金的基础上进行成分调整也是发展方向之一,如美国西屋电气公司通过将Zirlo 中Sn 的含量从1%下调至0.6%~0.8%,从而得到耐腐蚀性能和抗蠕变性能更加优异的Optimized Zirlo (OPT Zirlo)[26]㊂我国核用锆合金发展现阶段的目标是实现先进压水堆燃料组件用锆合金结构材料的自主产业化㊂目前,我表2㊀核反应堆常用锆合金应用情况[21-25]Table 2㊀The application of representative zirconium alloys in thenuclear reactor [21-25]Designation of zirconium alloy Reactor types UsageZr-2,Zr-4,BWR (boiling water reactor)Fuel cladding,spacers,fuel outer channel,et al .Zr-4,Zirlo,duplex,M5,MDA,NDAPWR (pressurized water reactor)Fuel cladding,guide tube,grid spacers,plug,fuel outer channel,access port,et al .Zr-2,Zr-4,Zr-2.5NbCANDU Pressure tube,calandria tube,fuel cladding,garter springs,plug,et al .E110VVER-440㊁VVER-1000Fuel cladding,grid spacersE110,E635RBMKFuel cladding,guide tube,fuel outer channel,spacers653All Rights Reserved.㊀第5期贾豫婕等:锆合金的研发历史㊁现状及发展趋势图3㊀新型锆合金的研发历程[22]Fig.3㊀The research and development route of a new zirconium alloy [22]国的锆合金研发及应用现状如下:不同型号核反应堆所用的Zr-4合金㊁M5合金和Zirlo 合金已经具备全流程的国产化制造能力,其中Zirlo 合金的入堆服役标志着我国核级锆材国产化目标的实现;国内自主研制的SZA 系列和CZ 系列锆合金堆内测试基本完成,工程化生产及性能评价已进入尾声,预计在2025年之前完成该系列新型锆合金的工程化应用;N36作为华龙一号中CF3核燃料组件的指定包壳材料,已在巴基斯坦卡拉奇核电站2号机组运行使用[27,28]㊂在自主产业化目标即将实现的同时,我国核用锆合金发展的部分问题仍未解决,例如自主研制的核用锆合金种类少,堆内测试地点少,堆内模拟数据库急需建立,针对锆材加工工艺㊁组织分析与堆内外服役性能之间的机理联系研究尚有不足等㊂2.4㊀核用锆材的生产加工技术进展及新型锆合金的开发改进锆合金的生产加工工艺与研制新型锆合金是发展核用锆材的关键㊂近年来,国内外在锆合金的生产加工技术以及合金成分优化方面都取得了重要进展㊂2.4.1㊀锆合金的加工技术进展核用锆合金管件的加工一般采用如图4所示的工艺流程[29],依次包括锆合金铸锭的熔炼㊁铸锭锻造㊁β相区淬火㊁热轧㊁反复的冷轧及退火,最终达到尺寸要求㊂改进锆合金的加工工艺是推动锆合金国产化的重要方面㊂目前,各个核发达国家均建成了从原子能级海绵锆到核图4㊀锆合金管件常规的加工热处理工艺流程图[29]Fig.4㊀Conventional processing and heat treatment process of Zr alloy tube[29]753All Rights Reserved.中国材料进展第41卷级锆合金结构材料的完整产业链㊂其中,美国的华昌㊁西屋电气,法国的法玛通等公司代表了锆合金产业化的世界先进水平㊂近年来,我国在锆合金的加工工艺方面取得了极大进展㊂在锆合金的熔炼工艺方面,采用非自耗真空电弧熔炼法可以得到组织均一㊁性能良好的锆合金,且铸锭的实际化学成分与预期的成分也相吻合;在锆合金的生产方面,通过工程化研究,我国已系统解决了Zr-4合金大规格铸锭(Φ=650mm 及以上)的熔炼技术及成分的均匀化调控技术㊁铸锭低温开坯技术㊁管材低温加工技术及织构调控技术㊁管材的表面处理技术㊁精整及检测技术等;在锆合金的热加工工艺方面,累积退火参数A 为锆锡合金管的加工提供了有效指导[30]㊂国内多家锆合金企业在生产加工技术方面也取得了很大的进步[31]㊂2010~2013年,中国核动力研究设计院联合西北有色金属研究院研制了采用国产两辊轧机两道次轧制㊁配合进口KPW25轧机生产Φ9.5mm ˑ0.57mm 管材的生产工艺,攻克铸锭均匀化熔炼㊁挤压感应加热等技术难题,推动了N36合金科研成果的转化㊂此外,国核锆业股份公司通过消化吸收美国西屋公司Zirlo 合金生产技术,成功熔炼得到核级Zr-4铸锭㊁R60702铸锭及Zirlo 返回料铸锭,实现了锆合金铸锭大规模国产化的新突破,建立了完整自主化的锆材加工生产线㊂综上所述,在锆合金生产加工工艺改进方面,国家还需加大投入力度,强化生产条件建设,加快具有自主知识产权锆合金的产业化生产步伐,实现核用锆合金研发生产加工的自主化,积极参与国际市场竞争㊂2.4.2㊀新型锆合金的研究与开发新型锆合金研发的主要趋势是开发多元合金,在Zr-Sn-Nb 系合金的基础上通过加入多种合金元素,同时提高锆合金的耐腐蚀性能及力学性能等㊂国内外新型核级锆合金的牌号及详细成分详见表3[31,32]㊂由表3可知,近20年来,随着核电技术的进一步发展,各国在新型锆合金成分筛选方面继续探索,美国㊁法国㊁韩国等在已经成功应用的锆合金基础上,开展了成分优化及新合金成分锆合金的研究㊂为打破国外核级锆合金厂商对锆合金成分的垄断,以中国核工业集团有限公司㊁国家核电技术有限公司㊁表3㊀国内外新型锆合金牌号及成分[31,32]Table 3㊀New Zr alloys developed by different countries [31,32]Designation of zirconium alloyChemical compositions /wt%SnNbFeCr Other Country OPT Zirlo0.60~0.790.80~1.200.09~0.13USAX5A0.500.300.350.25USA Valloy0.10 1.10~1.20USA VB 1.00 0.50 1.00USAM5 1.00 Sʒ(0.10~0.35)ˑ10-2Oʒ0.13~0.17France OPT M50.10~0.301.000.10~0.30France J11.80Japan J2 1.60 0.10 Japan J32.50 JapanHANA-40.40 1.500.200.10 Korea HANA-61.10Cuʒ0.05Korea N18(NZ2)0.80~1.200.20~0.400.30~0.400.05~0.10China N36(NZ8)0.80~1.200.90~1.100.10~0.40ChinaC7 0.10 Cuʒ0.01Sʒ0.025China CZ-10.800.250.350.10Cuʒ0.05China CZ-2 1.000.15 Cuʒ0.01China SZA-4/60.50~0.800.25~1.000.20~0.350~0.10Geʒ0.05or Cuʒ0.05or Siʒ0.015China 853All Rights Reserved.㊀第5期贾豫婕等:锆合金的研发历史㊁现状及发展趋势中国广核集团㊁西北有色金属研究院等为代表的核电材料龙头企业及研究机构从20世纪90年代初开始注重开发具有自主知识产权的锆合金㊂在前期研究的基础上,西北有色金属研究院进行了锆合金中试研究,确定了新一代锆合金的合金成分范围和加工工艺,研制出2种新型锆合金NZ2(N18)和NZ8(N36)㊂2009~2011年,西北有色金属研究院依托国家 863 计划项目成功研发了一种Zr-Nb 系锆合金 C7合金㊂2016年,由中广核集团自主研发设计的4组STEP-12核燃料组件和4组高性能核级锆合金(CZ 锆合金)样品管组件正式装入岭澳核电站二期1号机组,随反应堆进行辐照考验,这也标志着中广核集团全面掌握了核燃料组件的研究㊁设计㊁制造和试验技术㊂同时,国核宝钛锆业股份公司自主研发的SZA 新型锆合金紧跟锆合金发展趋势,在Zr-Sn-Nb 系合金的基础上添加微量合金元素Ge,Si 和Cu㊂试验结果表明,SZA 系列合金具有优良的耐腐蚀㊁吸氢和力学性能,有望用于CAP1400燃料组件中㊂2018年,在经过8年的技术攻关之后,我国突破了N36锆合金制备的核心技术环节,成功掌握了具有自主知识产权的完整N36锆合金工程化制备技术,已实现批量化生产,并成功应用于华龙一号 CF3燃料组件的制造,打破了国外长期垄断的局面,解决了我国长期的锆合金出口受限问题[27,28]㊂2.5㊀锆合金的微观组织演化锆合金的再结晶行为,第二相粒子的种类㊁尺寸及分布对锆合金的抗腐蚀性能㊁力学性能有很大的影响㊂此外,锆合金在加工过程中形成的强织构不仅影响锆合金中氢化物的分布特征,还是辐照生长㊁应力腐蚀开裂等的重要诱因㊂因此,锆合金的合金成分和加工工艺对其微观组织和织构演化有重要影响,系统研究锆合金的微观组织演化规律与加工工艺之间的关系是优化锆合金综合性能的基础㊂2.5.1㊀锆合金的微观组织特征核反应堆的极端服役条件要求加工后的锆合金具有均匀的微观组织㊁充分再结晶的晶粒和弥散分布的第二相颗粒等㊂研究表明,通过增加加工变形量或提高热处理温度都会加速Zr-1Nb 合金的再结晶进程[33](见图5)㊂合金元素Mo 的添加大大延缓了Zr-Nb 合金的再结晶过程[34],并且会显著降低Zr-Nb 合金的晶粒尺寸,进而降低合金的塑性㊂含Nb 锆合金的第二相大小及弥散程度与累积退火参数的相关性不强㊂因此,如何在Zr-Nb 合金中获得均匀弥散分布的第二相成为生产加工的重点问题㊂实验表明,N36(NZ8)锆合金中第二相粒子的尺寸㊁数量㊁分布与终轧前热处理的保温温度和保温时间相关[35]㊂经580ħ保温的N36(NZ8)锆合金具有细小且分布均匀的第二相粒子,其耐腐蚀性能较好㊂反之,保温温度的升高或保温时间的延长导致第二相粒子逐渐演化为带状分布,颗粒尺寸增加,耐腐蚀性能显著降低㊂此外,亦有研究发现在650~800ħ保温时,Zr-Nb-Fe 第二相粒子因结构不稳定发生溶解,同时基体析出β-Zr 相[36](见图6)㊂图5㊀Zr-1Nb 合金在580ħ下保温不同时间后的显微组织结构[33]:(a)冷轧变形态,(b)10min,(c)30min,(d)180min;(e)再结晶Zr-1Nb 试样在不同加工变形量㊁热处理温度及退火时间条件下的平均晶粒尺寸Fig.5㊀Microstructures of Zr-1Nb alloy annealed at 580ħfor various time [33]:(a)as-deformed,(b)10min,(c)30min,(d)180min;(e)average grain size of the recrystallized Zr-1Nb specimens subjected to different rolling stain,annealing temperature and annealing time953All Rights Reserved.中国材料进展第41卷图6㊀Zr-Sn-Nb 合金在不同温度保温后淬火得到的显微组织[36]:(a)原始组织,(b)590ħ保温50h,(c)650ħ保温15h,(d)800ħ保温40min,(e)900ħ保温10min,(f)Zr-Nb 二元合金相图富Zr 端Fig.6㊀Microstructure of Zr-Sn-Nb alloy after different temperature of heat preservation [36]:(a)as-received microstructure,(b)590ħ/50h,(c)650ħ/15h,(d)800ħ/40min,(e)900ħ/10min,(f)rich Zr zone of Zr-Nb binary alloy phase diagram2.5.2㊀锆合金的织构锆合金用于核燃料包壳管时,加工织构不仅影响其力学性能,还会影响其辐照生长㊁应力腐蚀开裂和氢脆等行为,因此,加工过程中对锆合金管材织构的控制是十分重要的[37,38]㊂对Zr-Sn-Nb-Fe 新型锆合金管冷轧后的织构分析结果表明[39],管材的织构类型与织构含量随冷加工变形量的变化而变化(如图7所示)㊂冷轧变形前,管材中的主要织构类型为<0001>//周向(TD)和<1120>//轧向(AD)㊂随变形量的增加,<1120>//AD 织构的含量急剧减少,同时<1010>//AD 织构的含量则快速增加,表明取向为<1120>//AD 的晶粒随变形量的增加逐渐转至<1010>//AD㊂图7㊀锆合金管材冷轧变形中织构组分的演化[39]:(a)管材变形锥体示意图,(b)织构组分变化曲线Fig.7㊀Variation of texture component in Zr cladding tube during cold rolling [39]:(a)deformation cone of Zr-Sn-Nb-Fe cladding,(b)tex-ture components evolution with strain [39]㊀㊀Zr-4合金带材是重要的核燃料组件定位格架结构材料,其织构影响辐照生长的倾向,进而影响格架的夹持力[40],因此,如何在生产中控制锆合金带材的织构是一个重要的课题㊂研究发现,β淬火板坯厚度㊁热轧总变形量㊁热轧温度等均会影响Zr-4合金板带材的织构,但热轧变形量的影响最显著[41-43],因此在工业生产中,应主要考虑通过调整热轧变形量来控制锆合金板带材的织构㊂此外,热轧变形量也会对锆合金板材的织构因子,即轧面法向织构因子f n ㊁轧向织构因子f 1以及横向织构因子f t 产生影响㊂增大板材的热轧总变形量能够增大织构因子f n ,同时减小织构因子f 1和f t [43]㊂2.6㊀核用锆合金的堆内(外)性能锆合金在服役过程中始终处于高温㊁高压㊁高应力㊁强辐照的服役环境,且锆合金在高温下极易与用作冷却63All Rights Reserved.㊀第5期贾豫婕等:锆合金的研发历史㊁现状及发展趋势剂的水发生反应,进而引发腐蚀㊁吸氢等一系列问题,因此锆合金的堆内外性能研究受到了广泛的关注㊂2.6.1㊀锆合金的腐蚀性能金属材料的腐蚀反应包括扩散㊁迁移㊁吸附㊁解吸㊁氧化还原和相变等步骤,如图8a所示,其中,影响腐蚀速度的关键因素是氧离子在氧化层中的扩散速率[44]㊂因此,依据Wagner-Hauffle假说[21],可以初步确定锆合金的合金化元素㊂随着锆合金合金成分多元化的发展趋势,腐蚀增重从单一的转折过程变成了复杂的多阶段性过程,如图8b所示,因此,阐明不同成分第二相粒子的耐腐蚀机理变得非常重要㊂通常,第二相的腐蚀速率比基体慢[45,46]㊂当基体被氧化时,内部的第二相被氧化锆包围,均匀弥散分布的第二相可以释放四方相氧化锆内应力,稳定致密柱状晶结构,减缓腐蚀增重转折点的出现㊂而在复杂的服役环境中,中子辐照会造成第二相的溶解和重新分布[47],基于此,有研究[48]建议选择尺寸较大的第二相,从而增加致密氧化层的稳定时间,提高合金耐腐蚀性能㊂图8㊀锆的腐蚀过程示意图[44]:(a)腐蚀中的物质传输,(b)不同合金的整体腐蚀增重曲线Fig.8㊀Illustration of corrosion mechanisms in Zr alloy[44]:(a)ions transportation in corrosion,(b)corrosion weight gain curves of different Zr alloys㊀㊀下面以含Nb(Nb>0.6%,质量分数)锆合金为例简要分析第二相对其腐蚀行为的影响㊂对于含β-Nb的锆合金,延长保温时间以增加β-Nb的析出不一定能够提高基体的耐腐蚀性能,因此,关于β-Nb对基体耐腐蚀性能的影响存在争议[49-52]㊂这种争议的主要原因在于,当合金中含有Fe,Cr,Cu等元素时,其扩散系数比Nb元素高,第二相析出更快,长时间的时效反而会导致其余第二相的析出长大,从而抵消β-Nb的抗腐蚀作用,最终基体的耐腐蚀性能升高不明显㊂总体而言,均匀弥散的β-Nb是具有耐腐蚀作用的,退火参数的选择需要综合不同的合金成分和加工工序进行调整,最终使β-Nb保持弥散㊁均匀的分布㊂近期的研究[53]阐明了β-Zr抗腐蚀能力提高的原因,由于β-Zr会发生共析反应,逐步分解为α-Zr和抗腐蚀性较好的β-Nb,保障了氧化层结构中致密而稳定的四方相氧化锆不断形成,从而降低了基体腐蚀速率㊂除却整体的腐蚀规律,局部腐蚀特征也是研究人员关注的重点,如疖状腐蚀和横向裂纹的产生㊂目前,关于疖状腐蚀的微观机理主要有2种:KUWAE氢聚集模型[54]和周邦新形核长大模型[55](如图9所示)㊂KUWAE氢聚集模型的机理解释为氢聚集在Zr/ZrO2界面上之后巨大的氢压导致氧化膜的破裂,从而使得腐蚀的进一步加剧㊂该模型主要适用于沸水堆[56],这一理论也可以解释大粒径的第二相粒子如何通过影响局部氢传输速度从而导致疖状腐蚀的产生[56]㊂周邦新形核长大模型的机理图9㊀疖状腐蚀机理整体认知:(a)KUWAE氢聚集模型[54],(b)周邦新形核长大模型[55]Fig.9㊀The mechanisms of nodular corrosion:(a)KUWAE model[54],(b)Zhou Bangxin model[55]163All Rights Reserved.中国材料进展第41卷解释是表面取向㊁合金元素㊁析出相局部不均匀导致了氧化膜的局部增厚现象,而氧化膜与基体的内应力不协调使得氧化膜的进一步长大,从而形成了疖状腐蚀㊂而氧化膜与基体的不协调也是横向裂纹产生的主要诱因㊂基于此,研究者[57,58]认为在ZrO2/Zr界面上由于晶体取向的各向异性,引发了第二相的偏聚及氧化层的各向异性生长,从而导致疖状腐蚀的形成[58]㊂随着锆合金合金化元素种类的增加,在今后的研究中,需重点关注不同合金元素带来的腐蚀性能差异,进而建立全面的腐蚀调控理论㊂此外,随着核反应堆向更高堆芯功率密度和更长服役寿命方向发展,对包壳和堆芯结构材料的服役可靠性提出了更高要求,尤其是对锆合金的超高温耐腐蚀性能提出了需求㊂日本福岛核事故中锆包壳与高温水蒸气反应引发氢爆,对现有核燃料组件的安全可靠性敲响了警钟,同时加速推动新型包壳和核燃料组件的研发㊂因此,研发事故容错燃料组件,预防失水事故(LOCA)时锆包壳与高温水蒸气反应引发重大安全事故,是当前的研究热点之一㊂目前,事故容错燃料领域主要包括3种研发思路[59]:①在现有包壳材料表面涂覆涂层,包壳涂层需具备抗氧化性㊁高附着性㊁热膨胀系数匹配㊁耐辐照㊁自我修复㊁高保护性以及制造工艺的稳定性等指标[60],目前的研究主要集中在铬涂层㊁SiC陶瓷涂层㊁高熵合金涂层等;②研究新型燃料包壳材料替换当前的锆合金㊂经过多年的研究,研究者们普遍认为钼合金㊁先进不锈钢[61]㊁SiC基陶瓷复合材料[62]㊁高熵合金[63]等具备代替锆合金的潜力;③研发新型核燃料组件以替代目前的整体UO2基燃料组件,从而大幅度提升核燃料组件的传热效率,降低堆芯温度㊂目前高性能燃料组件的设计思路主要包括美国提出的环形燃料组件[64]和麻花型扭转组件[65]等,其中环形燃料组件的发展较为成熟㊂2.6.2㊀锆合金的抗辐照损伤性能核用锆合金在核反应堆中的服役周期一般为12个月及以上,长时间高剂量中子辐照对锆合金的结构和性能产生重要影响,因此,锆的辐照损伤行为是评价其服役可靠性的关键问题之一㊂如图10所示,锆合金在中子辐照下容易引发辐照生长[66]㊁辐照硬化[67]和辐照蠕变[68]等㊂这些辐照效应会使锆包壳产生一系列服役安全问题,澄清其微观机制是调控锆合金抗辐照性能的关键㊂图10㊀锆合金的辐照效应:(a)辐照生长[66],(b)辐照硬化[67],(c)辐照蠕变[68]Fig.10㊀The irradiation damage of Zr alloy:(a)irradiation growth[66],(b)irradiation hardening[67],(c)irradiation creep[68]㊀㊀研究表明,辐照生长与<a>型和<c>型位错环密切相关,其中<c>型位错环的形成机理存在争议㊂最新研究[69]揭示了一种<c>型位错环形成的可能机制㊂纯锆在辐照后间隙型位错环的比例高于空位型位错环,额外的空位形成了二维三角形空位型缺陷㊂通过比较三角形空位缺陷与<c>型位错环的尺寸以及两者的能量,发现当三角形空位型缺陷达到临界尺寸后,会塌陷形成能量更低的<c>型位错环㊂氢的存在会降低表面能㊁稳定空位,促进了二维三角形空位型缺陷的形成㊂界面工程是提高材料抗辐照性能的重要方法㊂界面的引入可以加速辐照缺陷的湮灭,降低辐照缺陷的聚集,提高材料的抗辐照性能[70]㊂此外,界面还具有吸收辐照缺陷[71]㊁通过空位泵 [72]机制调控辐照点缺陷分布的作用㊂如何在锆合金设计中引入大量相界面是一个重要的挑战㊂研究者曾采用连续叠轧[73]和磁控溅射[74]技术制备层状锆合金,然而这些方法得到的材料各向异性强㊁加工成本高㊁工艺重复性差㊂近期,研究者采用热机械相变法[75],成功制备出了多级三维纳米层状双相锆铌合金,该合金具备优异的力学性能和抗辐照损伤能力㊂锆合金在服役过程中的辐照蠕变和辐照生长等严重影响其服役安全性㊂通常入堆后的锆材放射性较强,难以进一步细致表征,因此,模拟计算成为了研究和评价新型锆合金抗辐照性能的重要手段[76]㊂在宏观尺度上,一般采用有限元方法进行模拟㊂在介观尺度上,研究者通过VPSC(Visco-Plastic Self-Consistent)方法评估多晶蠕变和生长行为[77,78],通过速率理论[79]模拟缺陷演化并预测辐照硬化㊂在原子尺度上一般采用第一性原理计算和分子动力学模拟的方法研究点缺陷及其复合体的性质㊂最终,通过建立模拟平台实现对锆合金服役性能的跨尺度预测㊂综上所述,加强锆合金辐照损伤机理的研究,有利于促进新型抗辐照锆合金的设计㊂此外,加强多功能测试用263All Rights Reserved.。

Li2O-Al2O3-SiO2_系微晶玻璃的研究进展

第43卷第4期2024年4月硅㊀酸㊀盐㊀通㊀报BULLETIN OF THE CHINESE CERAMIC SOCIETY Vol.43㊀No.4April,2024Li 2O-Al 2O 3-SiO 2系微晶玻璃的研究进展任贝贝1,刘亚鑫1,黄㊀欣1,王㊀霆1,王㊀娜1,姜㊀宏2,熊春荣2,郝红勋1(1.天津大学国家工业结晶工程技术研究中心,天津㊀300072;2.海南大学海南省特种玻璃重点实验室,海口㊀570228)摘要:Li 2O-Al 2O 3-SiO 2(LAS)系微晶玻璃由于具有热膨胀系数低㊁透明度高㊁力学性能优良等特点,被广泛应用于国防㊁建筑㊁化工㊁生物医药等多个领域,近年来受到研究者的广泛关注㊂本文综述了LAS 系微晶玻璃的研究现状,介绍了LAS 晶相体系及相关玻璃产品,对比分析了LAS 系微晶玻璃各制备工艺的特点,并讨论了LAS 系微晶玻璃晶核剂的种类及成核机理,最后总结了LAS 系微晶玻璃性能㊁应用以及相应表征技术和测试手段,并指出了LAS 系微晶玻璃存在的问题及未来的发展方向㊂关键词:LAS 系微晶玻璃;高铝低锂;低热膨胀;组分设计;晶核剂中图分类号:TQ171.73㊀㊀文献标志码:A ㊀㊀文章编号:1001-1625(2024)04-1181-16Research Progress of Li 2O-Al 2O 3-SiO 2System Glass-CeramicsREN Beibei 1,LIU Yaxin 1,HUANG Xin 1,WANG Ting 1,WANG Na 1,JIANG Hong 2,XIONG Chunrong 2,HAO Hongxun 1(1.National Engineering Research Center of Industrial Crystallization Technology,Tianjin University,Tianjin 300072,China;2.Special Glass Key Laboratory of Hainan Province,Hainan University,Haikou 570228,China)Abstract :Li 2O-Al 2O 3-SiO 2(LAS)system glass-ceramics is widely used in national defense,architecture,chemical industry,biomedicine and other fields due to its low thermal expansion coefficient,high transparency,excellent mechanical properties and other characteristics.In recent years,it has received extensive attention from researchers.This article summarizes the current research status of LAS glass-ceramics,introduces the LAS crystal phase system and related glass products,compares and analyzes the characteristics of various preparation processes of LAS glass-ceramics,and discusses the types of LAS glass-ceramics nucleating agents and their nucleation mechanisms.Finally,the properties,applications,corresponding characterization techniques and testing methods of LAS glass-ceramics are summarized,and the existing problems and future development trends of LAS glass-ceramics are pointed out.Key words :LAS glass-ceramics;high aluminum and low lithium;low thermal expansion;component design;nucleation agent㊀收稿日期:2023-11-08;修订日期:2023-12-19基金项目:国家自然科学基金(U22A201195)作者简介:任贝贝(2000 ),女,硕士研究生㊂主要从事微晶玻璃方面的研究㊂E-mail:rbb_1124@通信作者:黄㊀欣,博士,副教授㊂E-mail:x_huang@郝红勋,博士,教授㊂E-mail:hongxunhao@0㊀引㊀言微晶玻璃是一种经过特定热处理程序进行成核和晶化而制备的多相固体材料[1],由玻璃相和微晶相共同组成,具有突出的热学㊁化学㊁光学和力学性能,目前被广泛应用于建筑㊁医学㊁微电子等领域㊂微晶玻璃最初由美国康宁公司的Stooky 在1957年研制成功,并确定了微晶玻璃的基本组成,开启了微晶玻璃的大门㊂微晶玻璃根据玻璃体系分为硅酸盐微晶玻璃㊁铝硅酸盐微晶玻璃㊁氟硅酸盐微晶玻璃㊁硼酸盐微晶玻璃及磷酸盐微晶玻璃,其中铝硅酸盐微晶玻璃以其明显的性能优势成为研究热点㊂铝硅酸盐微晶玻璃主要有四大系统:Li 2O-Al 2O 3-SiO 2系统㊁MgO-A12O 3-SiO 2系统㊁Na 2O-Al 2O 3-SiO 21182㊀玻璃材料与玻璃技术专题(II)硅酸盐通报㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀第43卷系统㊁ZnO-Al 2O 3-SiO 2系统㊂通常根据氧化物的组成来进行划分,其中LAS 系微晶玻璃的组成(质量分数)为:55%~70%SiO 2㊁15%~27%Al 2O 3和1%~5%Li 2O,MAS 系微晶玻璃的组成(质量分数)为:45%~66%SiO 2㊁17%~40%Al 2O 3和10%~27%MgO,NAS 系微晶玻璃组成(质量分数)为:45%~60%SiO 2㊁25%~40%Al 2O 3和10%~20%Na 2O,ZAS 系微晶玻璃组成(质量分数)为:45%~66%SiO 2㊁17%~20%Al 2O 3和10%~25%ZnO㊂其中Li 2O-Al 2O 3-SiO 2(LAS)系微晶玻璃具有强度高㊁热膨胀系数低且化学性质稳定等特点,是铝硅酸盐微晶玻璃中重要的一类,目前已经被广泛应用于光学领域㊁电子技术领域乃至特殊领域㊂例如,LAS 系微晶玻璃可以用于制造激光器㊁红外线探测器㊁光学望远镜等高精度光学器件,在军事侦察㊁导航㊁通信等方面发挥着重要作用㊂此外,LAS 系微晶玻璃还可以用于制造高强度㊁高硬度的防弹玻璃,保护士兵和军事设备的安全,甚至在深海探测视窗材料方面也表现出巨大应用潜力㊂基于此,本文总结了目前LAS 系微晶玻璃的国内外研究现状,综述了LAS 系微晶玻璃的组成㊁制备方法㊁表征手段和性能等方面的研究进展,并提出了LAS 系微晶玻璃目前存在的科学问题及未来的发展方向㊂1㊀LAS系微晶玻璃的组成及晶相体系图1㊀Li 2O-Al 2O 3-SiO 2系统三元相图(质量分数)[3]Fig.1㊀Ternary phase diagram of Li 2O-Al 2O 3-SiO 2system (mass fraction)[3]LAS 系微晶玻璃的主要组成是SiO 2㊁Al 2O 3㊁B 2O 3㊁Li 2O㊁Na 2O㊁ZrO 2和P 2O 5等㊂其中,SiO 2是组成基础玻璃网络结构的重要氧化物,形成的[SiO 4]四面体构成了玻璃的基本骨架㊂Al 2O 3是玻璃网络形成体,以[AlO 4]四面体结构形式存在,能够增强玻璃网络聚合度㊂B 2O 3也是玻璃网络形成体,有[BO 3]和[BO 4]两种结构形式,其中[BO 4]的聚合度比[BO 3]高㊂Li 2O 和Na 2O 等碱金属氧化物以及ZnO㊁MgO 等主要作为玻璃网络修饰体[2],通过引入非桥氧破坏网络结构,进而促进微晶析出㊂ZrO 2主要作为晶核剂,通过促进液-液相分离或非均质核ZrO 2纳米晶的析出促进析晶㊂P 2O 5在LAS 系微晶玻璃中的作用比较复杂,既可以作为晶核剂,也可以作为玻璃网络形成体㊂作为LAS 系玻璃中最重要的三种组成,Li 2O㊁Al 2O 3㊁SiO 2三者的含量对微晶玻璃性能产生直接影响㊂从LAS 系玻璃的三元相图(图1)中可以看出,当Al 2O 3含量较高时,析出的晶体主要是β-锂辉石固溶体或β-石英固溶体㊂当Li 2O 含量较高时,析出的晶体主要是Li 2O㊃SiO 2㊂基于LAS 系微晶玻璃中铝和锂的含量,将LAS 系微晶玻璃划分为高铝低锂微晶玻璃和高锂低铝微晶玻璃㊂1.1㊀高锂低铝微晶玻璃高锂低铝微晶玻璃中Li 2O 的摩尔含量约为20%,Al 2O 3的摩尔含量小于8%,主晶相为二硅酸锂(Li 2Si 2O 5)等锂硅酸盐晶体,其光学特性与天然牙齿接近,具有较好的生物相容性和机械性能,已被广泛应用于牙齿修复材料㊂Wang 等[4]通过调节P 2O 5含量,制备出具有较高弯曲强度(310MPa)和半透明特性的二硅酸锂微晶玻璃,可作为牙齿修复材料㊂Laczka 等[5]通过三元相图确定玻璃组分,制备出弯曲强度高达400MPa 且颜色和透明度与牙齿相近的LAS 系微晶玻璃㊂此外,高锂低铝微晶玻璃可以进行锂-钠和钠-钾两次深度离子交换,在不影响微晶玻璃透明度的同时使玻璃的裂纹压制层厚度与力学性能大大提升,其原理如图2所示,较大的Na +与Li +进行第一次离子交换,随后更大的K +将Na +交换出来,实现深度化学强化㊂Zhang 等[6]采用K +-Na +离子交换强化热压烧结法制备的高锂低铝微晶玻璃,结果表明,K +-Na +离子交换提高了高锂低铝微晶玻璃的力学性能和化学耐久性㊂Laczka 等[7]采用低温离子交换工艺对主晶相是二硅酸锂和硅铝锂的高锂低铝微晶玻璃进行强化㊂结果表明,通过使用KNO 3盐将较小的离子(Na +㊁Li +)与较大的离子(K +)进行离子交换,得到的高锂低铝微晶玻璃的弯曲强度为700~800MPa,相较强化前(300~450MPa)得到了显著提升㊂然而,锂原料价格昂贵,导致高锂低铝微晶玻璃成本较高㊂除此之外,高锂低铝微晶玻璃还存在很多问第4期任贝贝等:Li2O-Al2O3-SiO2系微晶玻璃的研究进展1183㊀题:1)主晶相二硅酸锂等锂硅酸盐晶体的模量和硬度较低,导致微晶玻璃的本征模量和本征硬度也相对较低,微晶及纳米晶体对玻璃的本征模量及强度增强有限,用于牙齿修复体尚有较大的破碎风险,且也无法满足国防尖端技术㊁微电子技术和航空航天等高精尖领域的需要㊂2)玻璃成分中Li2O含量高,长时间在口腔㊁海水等环境中使用时的抗侵蚀性能尚有待确认㊂3)虽然通过离子交换可以提高高锂低铝微晶玻璃的力学性能,但离子交换后微晶玻璃表面可能会发生去晶化现象,使微晶玻璃力学性能降低[8]㊂基于以上问题,在未来的研究中可筛选更高弹性模量和剪切模量的晶相,进而提高微晶玻璃的本征强度㊁硬度㊂图2㊀二硅酸盐微晶玻璃的离子交换原理示意图[9]Fig.2㊀Schematic diagram of ion-exchange principle of disilicate glass-ceramics[9]1.2㊀高铝低锂微晶玻璃高铝低锂LAS系微晶玻璃通常低热膨胀㊁高透明度和高机械强度等优点,且热膨胀系数在较大温度范围内可调㊂同时,相较于高锂低铝微晶玻璃,高铝低锂微晶玻璃的成本较低,且主晶相的晶体模量及硬度明显高于高锂低铝微晶玻璃,在特种玻璃领域具有更大潜质,因而一直受到研究者的关注㊂通过提高Al2O3含量可以增大玻璃网络结构孔隙,有利于吸收较大的K+,促进离子交换[10]㊂同时,增大Al2O3含量还可以提高玻璃的力学性能和化学稳定性㊂然而,过高的Al2O3含量会导致玻璃液黏度和表面张力增大,不利于熔化㊁澄清和成型[11]㊂因此,需要进一步探索基础玻璃的组成成分以降低玻璃的熔化和成型温度,或进一步开发新的特种玻璃熔化技术㊂此外,在高铝低锂微晶玻璃化学强化过程中只可以进行一次Na+-K+离子交换,交换强度大,但交换深度小,导致表面应力较高,抗冲击能力较低[12]㊂因此,需对熔盐配比㊁离子扩散规律㊁表面应力层分布以及强化工艺-表面结构-力学性能的关联进行更系统深入的研究[13-14]㊂高铝低锂微晶玻璃的主晶相包括β-石英固溶体㊁β-锂辉石晶体和β-锂霞石晶体,可通过调控微晶玻璃的基本组成成分得到不同主晶相的微晶玻璃,如表1所示㊂其中,β-石英固溶体作为主晶相的LAS系微晶玻璃对光的散射较低,透明度较高㊂德国肖特生产的零度®是β-石英固溶体微晶玻璃的典型代表,具有极低的热膨胀率,对可见光透明,能够满足航空航天㊁微型棱镜等的应用要求㊂美国康宁公司生产的vision®产品也是透明低膨胀β-石英固溶体微晶玻璃,耐热温度高达800ħ且能承受480ħ的冷热温差㊂但是,β-石英固溶体本征模量和本征硬度较低,无法满足深海探测材料等高端装备的要求㊂与β-石英固溶体微晶玻璃相比,β-锂辉石微晶玻璃光学性能较差,但其热膨胀系数低,抗热震性能较好,目前常应用于建筑㊁炊具面板等㊂而β-锂霞石晶体c轴表现出强烈的负膨胀性,使得含有大量β-锂霞石晶体的微晶玻璃在宏观上的热膨胀系数很低,甚至出现了负膨胀的现象[15]㊂美国康宁公司生产的Pyroceram®9606是以β-锂霞石为主晶相的微晶玻璃,密度低且耐1000ħ高温,美国航天局NASA采用此材料制造轻量化且满足相应热学和力学性能要求的零部件㊂β-锂霞石微晶玻璃的热膨胀系数较低,但其整体力学性能较差,兼具低膨胀系数和高力学性能的β-锂霞石微晶玻璃的制备将成为未来研究的重点㊂综上所述,玻璃的基本组成成分对LAS玻璃的主要析出晶相及性能有重要影响,若玻璃成分设计不理想则容易导致玻璃失透或玻璃力学性能达不到设计要求㊂例如,当配方中Li2O含量升高时,晶化容易析出β-石英固溶体晶体和β-锂霞石晶体,微晶玻璃光学性能提高,但力学性能大大下降;当Li2O含量减少时,β-锂辉石析出作为主晶相,微晶玻璃的力学性能增强但透明度大大降低㊂1184㊀玻璃材料与玻璃技术专题(II)硅酸盐通报㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀第43卷因此,需要在精准设计玻璃成分的基础上制备高模量高铝低锂微晶玻璃㊂尽管许多学者研究了微晶玻璃各个组成成分对玻璃结晶行为及对玻璃微观结构的影响,但不同的成分及含量在不同的微晶玻璃组成体系中发挥的作用并不相同,导致目前仍需通过大量的实验筛选来优化微晶玻璃的配方㊂因此,在未来的研究中有必要建立一个行之有效的理论模型来指导微晶玻璃的成分设计,制备出兼具高模量㊁高强度和高透明度的LAS系微晶玻璃,以满足如移动电子设备屏幕用玻璃㊁汽车玻璃㊁装甲车防弹玻璃㊁军用望远镜材料和深海装备视窗材料等民用和军用领域的需求㊂表1㊀高铝低锂微晶玻璃的主要组成[16]Table1㊀Main composition of high alumina and low lithium glass-ceramics[16]Material Mass fraction/%SiO2Al2O3Li2O K2O ZnO Na2O P2O5β-quartz solid solution GC55.4~68.819.2~25.4 2.7~4.50.1~0.6 1.0~1.50.2~0.6 1.0~7.2β-spodumene solid solution GC65.7~72.519.2~22.5 2.8~5.00.2~0.3 1.00.4~0.5 1.0β-lithium nepheline solid solution GC61.0~64.025.0~27.2 5.1~7.00.2~1.0 1.0~2.02㊀LAS系微晶玻璃的制备方法LAS系微晶玻璃的制备方法有很多,主要有整体析晶法㊁烧结法㊁溶胶-凝胶法㊁高分子网络凝胶法等㊂2.1㊀整体析晶法整体析晶法又称熔融法,基础玻璃与传统玻璃生产相同,经过高温熔融制备,然后通过一定的热处理程序进行核化和晶化得到微晶玻璃㊂整体析晶法工艺流程如图3所示㊂首先将玻璃的主要原料㊁辅助原料(澄清剂㊁助溶剂㊁着色剂㊁氧化剂等)和一定量的晶核剂均匀混合,于高温下熔融㊁澄清均化并调节到玻璃的成形温度后,采用压延㊁压制㊁吹制㊁拉制㊁浇铸㊁浮法等任意一种传统玻璃的成型方法使玻璃液成型㊂然后,经退火消除玻璃内部热应力,得到基础玻璃㊂通过热分析手段获得玻璃化转变温度T g㊁析晶温度T p等特征温度,然后制定合理的热处理程序使基础玻璃晶化和核化,得到微观结构良好的微晶玻璃㊂图3㊀整体析晶法工艺流程[17]Fig.3㊀Process flow of integral crystallization method[17]热处理是整体析晶法的关键,对微晶玻璃中晶体的类型㊁大小㊁体积分数和分布都有影响㊂制定合理的热处理程序需要确定成核温度㊁核化时间㊁析晶温度和晶化时间,最佳成核温度一般选在T g~T g+50ħ,最佳析晶温度选在结晶峰开始温度和结束温度之间,而最佳核化时间和晶化时间需要通过试验和表征确定㊂热处理可分为一步热处理法和两步热处理法,一步热处理法是在析晶温度下保温一定时间,成核和结晶在基础玻璃中同时进行的方法,具有处理时间短㊁工艺简单等优点,但由于晶核析出之后就开始生长,最后得到的微晶玻璃制品结晶度低,晶体尺寸较大㊂两步热处理法是先将基础玻璃在成核温度下保存一定时间,使玻璃中析出大量细小的晶核,然后再将玻璃在析晶温度下处理,使晶体充分生长㊂楼贤春等[18]探究了热处理程序对LAS系微晶玻璃热膨胀和强度的影响,结果表明LAS系微晶玻璃热膨胀受晶化温度和晶化时间的影响较大,而强度则主要受晶化温度和核化时间的影响,最终确定最佳热处理工艺,得到主晶相为β-石英的零膨胀高透明度LAS系微晶玻璃㊂Xiao等[19]研究了析晶温度对含P2O5的LAS系微晶玻璃晶相衍变㊁微观结构和热膨胀系数的影响㊂当析晶温度较低时,主晶相为硅锂石,热膨胀系数较小;随热处理温度升高,β-锂辉石析出成为主晶相,热膨胀系数增大;析晶温度升高会使LAS系微晶玻璃中的晶体粗化㊂整体析晶法的一大优势就是可以利用任意一种传统玻璃的成型方法使玻璃液成型,包括压制法㊁压延法和浇铸法等[20]㊂其中,压制法是将熔制好的玻璃液注入成型模具中,使玻璃液在压力与摩擦力的作用下均匀地填充在上模具㊁模环和成型模具之间㊂使用压制法制备微晶玻璃的一个典型案例是美国康宁公司生产第4期任贝贝等:Li2O-Al2O3-SiO2系微晶玻璃的研究进展1185㊀的Li2O-Al2O3-SiO2系微晶玻璃厨具㊂压延法是将合格的玻璃液在辊间或者辊板间压延成平板状玻璃,美国康宁公司利用压延法制备了Li2O-Al2O3-SiO2系低膨胀微晶玻璃电磁炉面板㊂浇铸法是将合格的玻璃液浇铸到预热好的金属模具中,待金属液冷却成型后脱模㊁退火得到基础玻璃,主要用于制备片状㊁块状或柱状等形状简单的玻璃[16]㊂日本小原㊁国内光明光电的飞鸟都是采用浇铸法制备㊂这三种成型工艺各有利弊,对比如表2所示㊂表2㊀整体析晶法中不同玻璃成型工艺对比[20]Table2㊀Comparison of different glass forming processes in integral crystallization method[20]成型方法压制法压延法浇铸法优势①形状准确;②工艺简单;③生产能力高①适合生产平板玻璃,不需要进行整形㊁切割工序,生产效率高,生产成本低;②对不同微晶玻璃品种的适应性广,玻璃被压辊急冷成型,可以阻止玻璃析晶①熔化炉小,可灵活调整玻璃品种;②采用光学玻璃工艺生产,玻璃质量高;③成型过程中几乎无凉玻璃滞留,不易析晶劣势①不能制备下阔上狭的玻璃制品,否则上模具无法取出;②不能生产薄壁和内腔在垂直方向长的制品;③制品表面不光滑,常有斑点和模缝①压延成型后玻璃表面粗糙,要进行研磨㊁抛光等后续处理工序;②进入压延机前玻璃在供料口边部或底部容易形成滞留低温区玻璃,容易析晶①生产规模小,产能低;②需进行整形㊁切割㊁研磨㊁抛光等多项后续处理工序,物料损耗大,生产效率低,生产成本高浮法工艺也是一种高温熔融析晶方法,具有能耗低㊁产量高㊁质量优等特点,是生产高铝和平板微晶玻璃的主流工艺方法㊂制备过程为:熔融的玻璃液从池窑连续流入充有保护气体(N2及H2)的锡槽内并漂浮在金属锡液面上,在重力和表面张力的作用下,摊成厚度均匀㊁平整㊁抛光的玻璃带,冷却硬化后脱离金属液,再经退火㊁晶化㊁切割得到浮法微晶玻璃产品㊂目前,海南大学姜宏教授团队围绕浮法玻璃进行了诸多研究,包括全氧燃烧技术㊁熔化过程控制技术㊁玻璃熔窑的设计㊁浮法表面发朦原因及解决策略等,不断优化浮法玻璃生产工艺,获得了诸多成果[21-24],但是通过浮法生产LAS系微晶玻璃还有许多问题需要解决㊂比如LAS系微晶玻璃黏度大,熔融温度高,需要加入碱金属氧化物或碱土金属氧化物作为助熔剂来降低LAS玻璃的熔融温度和黏度,但碱金属氧化物/碱土金属氧化物的引入会带来热膨胀系数增大㊁强度降低等问题㊂谢军等[25]探究了不同CeO2含量对浮法LAS系微晶玻璃黏度和结构的影响,结果表明:当CeO2含量较低时, CeO2作为玻璃网络修饰体会破坏玻璃网络结构,降低玻璃黏度;当CeO2含量较高时,会造成较大的局部键力,增强玻璃网络结构㊂Zheng等[26]探究了不同含量的氟离子对LAS系微晶玻璃黏度和结晶行为的影响㊂结果发现,由于相似的半径,氟离子可以取代桥氧离子后玻璃网络聚合度降低,从而使玻璃黏度和熔融温度降低,满足浮法的工艺条件㊂同时,氟离子可以促进相分离,降低结晶活化能,促进结晶,得到主晶相为β-锂辉石的LAS系微晶玻璃㊂中国晶牛集团自主研发了具有极低热膨胀㊁高透明度㊁优异机械性能和化学稳定性的浮法LAS系微晶玻璃,建成了世界首条浮法透明航天微晶玻璃生产线,填补了世界浮法微晶玻璃的空白㊂然而,需要认清目前国内浮法LAS系微晶玻璃仍处于探索阶段,虽然已经取得了一些研究成果,但要实现规模化生产还面临许多问题㊂不过可以肯定,浮法仍是今后LAS系微晶玻璃生产工艺发展的一个重要方向㊂综上,整体析晶法能够保证成核和晶体生长在玻璃内部均匀发生,得到的微晶玻璃孔隙率较低,致密性好㊂但随着高铝低锂微晶玻璃应用领域的扩展,在利用整体析晶法制备LAS系微晶玻璃的过程中,还存在着析晶过程及微晶玻璃结构调控机制与方法不明㊁熔融温度高㊁澄清和均化困难等技术问题㊂在未来的研究中,可重点关注以下研究方向:微晶玻璃熔化过程中温度场与玻璃性能之间的关系;电极加热和火焰加热等加热方式相互耦合与匹配对玻璃液澄清及均化的影响;如何利用计算机技术构建熔化模型,建立玻璃熔制过程中动力学和热力学方程;研究玻璃熔化场景中的玻璃黏度㊁表面张力㊁玻璃成分分相及偏析行为等等㊂最终,制备出兼具高模量㊁高强度和高透明度的LAS系微晶玻璃㊂2.2㊀烧结法烧结法一般不需要加入晶核剂,得到的是表面析晶的微晶玻璃㊂其基本工艺为:原料混合均匀后进行高温熔融,玻璃液澄清均化后倒入冷水中水淬,干燥㊁粉碎,得到一定颗粒大小的玻璃熔块,根据玻璃的成型方法确定玻璃颗粒的粒度范围㊂之后,对成型玻璃进行光学膨胀分析,得到适宜的烧结温度,烧结晶化㊁退火后即可得到微晶玻璃(图4)㊂烧结法可分为玻璃粉末的烧结和玻璃颗粒的烧结,LAS系微晶玻璃常采用粉末1186㊀玻璃材料与玻璃技术专题(II)硅酸盐通报㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀第43卷烧结法㊂玻璃粉末的粒度对微晶玻璃的微观结构和性能有很大的影响㊂若粉末太小,析晶温度低于烧结温度,晶体的析出会影响颗粒迁移和玻璃相流动,使烧结致密过程恶化,得到的微晶玻璃孔隙率偏大;若粉末太粗,最后得到的微晶玻璃晶体尺寸大且分布不均,所以要严格控制玻璃粉末的粒度㊂玻璃粉末成型时,大都采用压制成型的方法,压制压力也对微晶玻璃制品有一定的影响㊂Figueira等[27]用粉末烧结法制备LAS系微晶玻璃时,发现压制成型时压力越大,最后得到的微晶玻璃致密性越好㊂图4㊀烧结法制备微晶玻璃流程图[17]Fig.4㊀Process flow chart of preparing glass-ceramics by sintering[17]烧结法与整体析晶法相比,烧结温度低且耗时较短,但因为烧结法的结晶机理是表面结晶,表面晶体与内部玻璃相密度相差较大会造成失配,导致制备的微晶玻璃孔隙率更高㊂孔隙形成机理如图5所示,在烧结过程中,孔隙沿着晶体生长方向扩展,晶体析出会增加玻璃黏度,导致内部残余玻璃相无法及时填充孔隙,微晶玻璃致密性恶化,孔隙率增大,对微晶玻璃制品的力学性能不利㊂解决方法是在玻璃结晶之前通过热处理使玻璃达到较高的致密化程度,最佳热处理条件需要研究者进行大量探索㊂此外,基础组成成分㊁烧结温度㊁烧结时间等因素都会对微晶玻璃制品的性能产生很大影响㊂Soares等[28]通过调配组成成分,获得了具有低热膨胀(0.34ˑ10-6K-1)和高烧结性能(孔隙率仅为(0.4ʃ0.1)%)的LAS系微晶玻璃㊂Lutpi等[29]探究了不同烧结时间下LAS系微晶玻璃的烧结行为,结果表明,延长烧结时间对LAS系微晶玻璃的微观结构有显著影响,烧结3.5h的LAS微晶玻璃,孔隙率降低,结晶率增加,具有较强的抗热冲击能力㊂目前,工业上常以高炉渣㊁粉煤灰等工业废料和矿物为原料,利用烧结法制备微晶玻璃,以达到保护环境㊁节约资源的目的㊂然而,由于影响因素众多且生产的微晶玻璃产品可能存在孔隙,产品的光学性能和力学性能有所降低,所以烧结法制备的微晶玻璃目前常应用于建筑装饰,尚未涉及航空航天㊁微电子㊁国防尖端技术等应用领域㊂图5㊀孔隙形成机理[30]Fig.5㊀Pore formation mechanism[30]第4期任贝贝等:Li2O-Al2O3-SiO2系微晶玻璃的研究进展1187㊀2.3㊀溶胶-凝胶法LAS系微晶玻璃黏度高,导致熔融温度和加工温度非常高,所以低温制备LAS系微晶玻璃已经成为一个热门话题,溶胶-凝胶法被认为是低温制备LAS系微晶玻璃最有潜力的方法之一㊂Wang等[31]采用溶胶-凝胶法制备了LAS系微晶玻璃,相比于1600ħ传统熔融结晶法,此法在1200ħ下便可完成㊂溶胶-凝胶法制备微晶玻璃的过程如图6所示,将金属有机物或无机化合物作为前驱体,与水㊁醇等充分混合形成溶液,通过水解和缩合反应,形成稳定的透明溶胶体系,溶胶陈化后,胶粒缓慢聚合,形成以无机物或金属醇盐为骨架的三维空间网络结构的凝胶[32],随后通过干燥㊁成型㊁晶化等步骤得到微晶玻璃㊂Xiao等[33]采用溶胶-凝胶法和粉末压制成型工艺,成功制备了含0%~10%(质量分数)P2O5的LAS系微晶玻璃㊂试验过程中烧结温度为950ħ,远低于整体析晶和烧结工艺,且β-锂辉石是唯一的晶相,微晶玻璃制品在25~700ħ有很低的热膨胀系数㊂除低温外,溶胶-凝胶法制备微晶玻璃过程中可按照原料配比析出高纯度晶相,但微晶玻璃氧化物原料成分对析晶性能有很大影响㊂夏龙等[34]采用溶胶-凝胶法制备LAS系微晶玻璃,发现微晶玻璃完全按照原料配方㊁化学计量比生成了β-锂辉石LAS微晶玻璃㊂Chatterjee等[35]以正硅酸乙酯(TEOS)㊁气相二氧化硅和稻壳灰三种不同来源的二氧化硅为原料,采用溶胶-凝胶法制备了LAS粉体,并研究了它们对粉体性能的影响㊂结果表明,与稻壳灰硅源相比,TEOS和气相硅源下β-辉闪石和β-锂辉石的结晶速度更快㊂溶胶-凝胶法虽然具有温度低㊁纯度高㊁耗时短等诸多优点,但仍然存在许多问题尚未解决,如前驱体成本高㊁后期热处理时间长㊁制品收缩大㊁易变形等,若采用金属醇盐作为原料还会对环境造成污染[36]㊂上述问题在一定程度上限制了溶胶-凝胶法的工业普及㊂图6㊀溶胶-凝胶法工艺流程图[17]Fig.6㊀Process flow chart of sol-gel method[17]2.4㊀高分子网络凝胶法高分子网络凝胶法以无机盐水溶液作为原料,通过丙烯酰胺自由基发生聚合反应以及N,N-亚甲基双丙烯酰胺交联反应,高分子链被连接起来构成网络从而形成凝胶[37],高分子网络凝胶法工艺流程如图7所示㊂吴松全等[38-39]利用高分子网络凝胶法制备出LAS系微晶玻璃超细粉体,并探究了ZrO2对高分子网络凝胶法制备的LAS系微晶玻璃析晶行为的影响㊂结果表明,随着ZrO2含量增加,析晶活化能降低,β-石英固溶体析出,析晶速率降低,阻碍了β-石英固溶体向β-锂辉石的转化㊂李亚娟等[39]探究了Y2O3对高分子网络凝胶法制备的LAS系微晶玻璃性能的影响,结果表明Y2O3掺杂会促进β-石英固溶体向β-锂辉石的转变且起到细化晶粒的作用,但Y2O3掺杂也会使LAS系微晶玻璃的热膨胀系数增大㊂贾鹏等[40]通过加入TiO2调节高分子网络凝胶法制备的LAS系微晶玻璃的析晶性能,结果表明,TiO2可以降低析晶活化能,细化晶粒㊂因此,高分子网络凝胶法具有原料简单㊁合成速度快㊁产物纯度高等显著优势㊂但与此同时,高分子网络凝胶法仍存在化学试剂用量大以及聚合温度较难精确控制等问题[41],此外,晶核剂对高分子网络凝胶法制备的LAS系微晶玻璃析晶行为和性能的影响及其机理尚不清晰,这也是今后高分子网络凝胶法制备LAS系微晶玻璃的一个重要研究方向㊂综上,传统整体析晶法和烧结法制备的LAS系微晶玻璃产品质量好,但制备过程中所需温度较高,能耗大,对玻璃熔窑要求高;新兴的溶胶-凝胶法和高分子网络凝胶法制备条件较温和,但存在对环境污染大㊁微晶玻璃制品易收缩变形等缺点,尚未有工业化的迹象㊂因此未来不仅需要探索开发LAS系微晶玻璃生产新。

锂辉石浸出液提锂除杂规律研究

Vol.53 No.4Apr.,2021第53卷第4期2021年4月无机盐工业INORGANIC CHEMICALS INDUSTRYDoi:10.11962/1006-4990.2020-0315「开放科学(资源服务)标志识码(OSID)锂辉石浸出液提锂除杂规律研究谭博,刘香环，刘旭东,易美桂（四川大学化学工程学院，四川成都610065）摘要:碳酸锂是一种基础锂盐，不仅广泛应用于传统化工行业,也是生产锂电池的重要原料，近年来锂电产业蓬勃发展，极大推动了原料碳酸锂的提取与制备研究。

为了提取锂辉石中的锂来制备碳酸锂，利用沉淀溶解-平衡理论分析锂浸岀液的除杂规律。

对锂辉石进行转型焙烧、酸化焙烧、浸取，锂辉石中98%左右的锂可进入液相，得到锂浸岀液，然后根据溶解平衡理论确定3步除杂净化条件：1冤中和pH 至6.5除大部分AF +和 Fe 3+；2）加入氧化剂将Fe 2+氧化成Fe 3+,调pH 至8.0除Fe 3+；3冤调pH 至10.0,加入理论量碳酸钠（以液相Ca 2+计），最终Al 3+、Fe 3+、Mg 2+等浓度低于10^ mol/L,Ca 2+质量分数约为2xl0-5。

关键词：碳酸锂；锂辉石；除杂中图分类号:TQ131.11 文献标识码:A 文章编号：1006-4990（2021 ）04-0056-05Study on law of lithium extraction and impurity removal from spodumene leaching solutionTan Bo , Liu Xianghuan , Liu Xudong , Yi Meigui(School of Chemical Engineering, Sichuan University , Chengdu 610065, China)Abstract : As a basic lithium salt , lithium carbonate is not only widely used in the traditional chemical industry , but also an important raw material for the production of lithium batteries.In recent years , the booming development of lithium battery in dustry has greatly promoted the research on extraction and preparation of raw material of lithium carbonate.In order to extractlithium from spodumene to prepare lithium carbonate , the precipitation dissolution equilibrium theory was used to analyze the impurity removal law of lithium leaching solution.In this study , spodumene from a domestic place was used as raw material toexplore the process rules of preparing lithium carbonate.The surface of spodumene was smooth and dense , so it was difficult toreact with most acid and alkali (soluble in hydrofluoric acid ).Therefore , through the early exploration of reaction temperature and reaction time , 琢-spodumene could be completely transformed into 0-spodumene under 1 050 益 with calcination time of30 minutes.After calcination transformation , the raw material of 0-spodumene could be mixed with sulfuric acid to calcine toconvert lithium into soluble lithium.As a result , about 98% of lithium in spodumene could enter the liquid phase and get thefinal lithium leaching solution.In order to prepare high-purity lithium carbonate , the process of purification and impurity re moval was explored to obtain more accurate pH range of each ion precipitation.The pH range of Al 3+, Fe 2+, Fe 3+, Mg 2+, Ca 2+ precipitation was discussed by using the principle of dissolution equilibrium through HSC thermodynamics software and con sulting relevant data.Then the three-step decontamination purification condition was determined according to the dissolution equilibrium theory ： 1)neutralizing the pH to 6.5 to remove Al 3+ and Fe 3+；2)adding oxidant to oxidize Fe 2+ to Fe 3+ and adjustingthe pH to 8.0 to remove Fe 3+； 3 )adjusting the pH to 10.0 by adding the theoretical amount of carbonic acid sodium (calculatedby Ca 2+ in the liquid phase ),final concentration of Al 3+, Fe 3+, Mg 2+, etc.was lower than 10-6 mol/L , and mass content of Ca 2+ was about 2x10-5.Key words : lithium carbonate ； spodumene ； impurity随着全球能源危机和环境污染问题日益突出, 节能、环保等有关行业的发展被高度重视,发展新能源已在全球范围内达成共识。

火攻矫正工艺中英文

1 火工矫正的目的Purposes火工校正重要是用来消除钢板扎制、热切割、焊接产生的残余应力和变形。

在焊接钢结构制造中最重要是用来对焊接变形的校正。

Distortion correction by flame is mainly used for eliminating the resident strength and distortion from plates rolling, heat cutting and welding. In welding steel structures this process mainly applies for the correction of welding distortion.2 火工校正的原理Principle火焰矫正是运用金属热胀冷缩的物理特性，采用火焰局部加热金属，热膨胀部分受周边冷金属的制约，不能自由变形，而产生压塑性变形，冷却后压塑性变形残留下来，引起局部收缩，即在被加热处产生积聚力，使金属构件变形获得矫正。

Flame correction is based on the characteristic of steel expanding with heat and contracting with cold. After partial heating of the steel, the pressing distortion coming from pressure of heated parts will contract when cooling down, creating strength in pre-heated place, so as to correct the distorted metals.3 焊接变形的种类Distortion Groups3.1 纵向收缩变形Longitudinal Contract Distortion构件焊后在焊缝方向产生收缩。

硫酸镁建筑材料制备及性能研究

硫酸镁建筑材料制备及性能研究马梦娜（陕西工业职业技术学院，咸阳712000）摘要：硫酸镁水泥具有质轻、高强、高环保以及低耗能等特点，是一种新型的胶凝材料，其在建筑领域有着重要的应用前景。

本论文采用发泡技术，选用硫酸镁水泥作为主要的原材料，制备硫酸镁基轻质材料，并通过单一变量的实验方法，研究了不同的稳泡剂剂量、水灰比条件下制备的材料的力学性能以及软化系数性能，为以后的硫酸镁建筑材料的研究奠定了基础，同时为以后的应用提供了理论和试验的依据。

关键词：硫酸镁；材料表征；力学强度；衍射分析中图分类号：TU528文献标识码：A文章编号：1001-5922（2021）01-0012-04 Study on Preparation and Performance of MagnesiumSulfate Building MaterialsMa Mengna（Shaanxi Polytechnic Institute,Xianyang712000,China）Abstract：Magnesium sulfate cement has the characteristics of light weight,high strength,high environmental pro⁃tection and low energy consumption.It is a new type of cementitious material and has important application pros⁃pects in the field of construction.This paper adopts foaming technology,selects magnesium sulfate cement as the main raw material,prepares magnesium sulfate-based lightweight materials,and through a single variable experi⁃mental method,the mechanical properties and softening coefficient performance of materials prepared under differ⁃ent foam stabilizer dosages and water-cement ratio conditions were studied,which laid the foundation for future re⁃search on magnesium sulfate building materials,and at the same time provided theoretical and experimental basis for future applications.Key words：magnesium sulfate;material characterization;mechanical strength;diffraction analysis0引言我国城镇化的不断发展，人民生活质量的不断提高，使得国民对于环保的意识逐渐提高。

中国科学院大连化学物理研究所

3
（简述研究计划的可行性、先进性和创新性，理论和现实意义）可行性分析
1. 理论意义：
有机-无机杂化钙钛矿太阳能电池自从2009年被研究以来，已经取得了突飞猛进的进步，其最
高光电转换效率已达到23.7%。钙钛矿材料有着优异的吸光范围、较高的光电转换效率、较高的电
荷迁移率等优点，适合作为光敏层应用到太阳能电池上。但是钙钛矿电池的缺点也是很明显的，
本
人
承本人签字：蒋晓庆
2019 年 5 月 5 日
诺
5
巨大的环境问题，甚至是经济安全问题。
这些问题使中国人意识到发展可再生能源对中国可持续发展的重要意义。中国可再生能源市场广大，有着良好的可再生能源的经济环境。因此，无论从能源市场需求、环境需要，还是中国经济安全的角度，在中国发展太阳能产业具有重要的现实意义和战略意义。
本研究计划面向国家解决能源问题的重大战略需求，以光-电转换为核心的光电转换材料和器件，有望在可再生能源的开发和能源高效利用方面提供重要的技术支撑。目前，基于杂化钙钛矿材料的光电器件研究已成为全球光电能源领域的研究热点，但该技术的发展目前仍处于初级阶段，这对我国传统光电产业的升级换代是非常难得的机遇与挑战。
将功能化的季铵盐修饰到钙钛矿晶界是可行的。
功能化双季铵盐可以将晶界缝合起来以减少外界水分子和氧分子通过钙钛矿晶界处进入钙钛
矿内部对钙钛矿材料进行破坏。所以用功能化双季铵盐提高器件长期耐
热耐湿性能是可行的。双季铵盐修饰钙钛矿界面还可以钝化钙钛矿晶界处的缺陷态减少电荷
在晶界传输过程中的能量损失，所以用功能化双季铵盐来提升器件的光电转化性能是可行的。
位要组成部分的空穴传输材料的合成工艺复杂、稳定性差、成本过高以及对电极使用的

石墨烯制备及其在新能源汽车锂离子电池负极材料中的应用

石墨烯制备及其在新能源汽车锂离子电池负极材料中的应用田晓鸿（西安航空职业技术学院，西安710089）摘要：新能源汽车锂离子电池对于负极材料的节能环保性要求较高，而石墨烯作为新型的碳材料，因低成本、高性能而成为新型的负极材料，而针对氧化石墨法制备流程复杂、存在污染性，且制成的微米级团聚颗粒石墨烯电化学性能受限问题，文章采用机械液相剥离的规模化制备工艺，将石墨烯与石墨复合制备成石墨烯复合材料，通过实验方法测定其作为锂离子电池负极材料的电化学应用性能，结果表明与石墨复合后，可有效优化石墨烯负极材料的使用性能，更好的满足新能源汽车发展要求。

关键词：石墨烯；负极材料；电化学性质；锂离子电池中图分类号：U469.72；TM912文献标识码：A文章编号：1001-5922（2021）01-0183-04 Preparation of Graphene and Its Application as Anode Materials for Lithium Ion Batteries of New Energy VehiclesTian Xiaohong（Xi'an Aeronautical Polytechnic Institute，Xi'an710089，China）Abstract：New energy automobile lithium-ion battery has high requirements for energy-saving and environmental protection of anode materials.Graphene,as a new carbon material,has become a new type of anode material due to its low cost and high performance.However,in view of the complicated preparation process of the graphite oxide method,the presence of pollution,and the limited electrochemical performance of the micron-sized agglomerated particles,this paper adopts the large-scale preparation process of mechanical liquid phase exfoliation to prepare graphene and graphite composites into Graphene composite material,through the experimental method to determine its electrochemical application performance as a lithium-ion battery anode material.The results show that the per⁃formance of graphene anode material can be effectively optimized after compounding with graphite,which can bet⁃ter meet the development requirements of new energy vehicles.Key words：graphene;anode material;electrochemical properties;lithium ion battery0引言随着电动汽车技术及保有量的不断发展，为实现节能减排的目的，对锂离子电池制备及使用性能提出了更高的要求。

污泥无害化处理及其在烧结砖中的应用

现在城市化步伐愈来愈快，城市化的发展必然带来污水量不断增多，污水处理厂产生的污泥处理问题渐渐得到了重视。

目前，对污泥处理解决依然存在问题，污泥处理问题愈加严重。

将污泥进行简单干燥处理或直接利用，既没有对污泥中的重金属进行固化、钝化处理，也没有对其中的微生物进行消杀，这些污染物通过大气、水、食物链等多种途径造成二次污染，危及人类健康。

《“十四五”城镇污水处理及资源化利用发展规划》（发改环资〔2021〕827号）要求城市污泥无害化处理处置率达到90%以上，破解污泥处置难点，实现污泥减量化、无害化、资源化处置。

现有污泥处置能力不能满足需求。

为了加快压减污泥填埋规模，积极推进污泥资源化利用，“十四五”期间，要求新增污泥（含水率80%的湿污泥）无害化处置设施规模不少于2万t/d ，必须要求污泥无害化处置途径。

鼓励采用热水解、厌氧消化、好氧发酵、干化、碳化等方式进行无害化处理，提升城市污泥协同综合处置能力。

把污泥的减量化、无害化处理工艺与技术融合到烧结砖的生产工艺中，把经过无害化处置的污泥生产烧结砖。

利用烧结砖瓦企业的余热实现污泥脱水减量化、无害化、资源化及污泥的进一步碳化，具有污泥处置量大、处置过程无害化、性能优异的优势。

处置后的污泥资源化利用是砖瓦行业向固废资源化利用方向转型升级的途径之一和发展方向，可用于生产普通烧结砖、烧结保温砌块、清水砖等墙体材料。

同时，污泥的资源化利用，为城市固体废弃物综合利用找到一个好途径，参与城市生态文明圈的建设，为城市生态建设做出贡献。

污泥主要是城市污水处理和工业废水处理产生的固体废物，分为城市污泥和工业污泥两大类。

前者属于一般固体废物，是烧结砖行业主要资源化利用的对象，而后者则需要具体对待。

城市污泥是污水处理厂净化污水以后产生的固体废物，是沉淀污泥和生物处理污泥的混合物，水分高达80%左右。

污泥里面含有病原体、重金属、微生物等有害物质，要将污泥中的水分脱去是一件非常困难的事情。

甘蔗的制作流程科学科普文

甘蔗的制作流程科学科普文英文回答：Sugarcane Production Process.Sugarcane, a tall perennial grass, is cultivated in tropical and subtropical regions worldwide. Its primary product is sugar, an essential sweetener and ingredient in various food and beverage industries. The production of sugarcane involves several stages, from cultivation to processing, to obtain the final sugar product.Cultivation.Land Preparation: The land is cleared, plowed, and fertilized to provide optimum conditions for sugarcane growth.Planting: Sugarcane is typically propagated through stem cuttings known as "setts." These setts are planted inrows and watered regularly.Crop Management: Sugarcane requires regular irrigation, fertilization, and pest control to ensure healthy growthand high yields. Harvesting typically occurs after 10-12 months.Harvesting.Burning: Prior to harvesting, the sugarcane fields are often burnt to remove leaves and debris, facilitatingcutting and harvesting.Cutting: Specialized harvesting machines or manual laborers cut the mature sugarcane stalks at the base.Transport: The harvested sugarcane is transported to processing mills for further processing.Processing.Crushing: The sugarcane stalks are crushed to extractthe juice, which contains sucrose.Clarification: The sugarcane juice is filtered and treated with chemicals to remove impurities and clarify it.Evaporation: The clarified juice is heated and evaporated to concentrate the sucrose content.Crystallization: The concentrated juice is cooled and crystallized, forming sugar crystals.Centrifugation: The sugar crystals are separated from the molasses by centrifugation.Refining.Washing and Drying: The sugar crystals are washed and dried to remove impurities.Decolorization and Filtration: Activated carbon or other agents are used to decolorize the sugar. The sugar is then filtered to remove any remaining impurities.Packaging: The refined sugar is packaged in various forms, such as granulated, brown, or powdered sugar, for distribution and consumption.Byproducts.Molasses: A thick, dark liquid byproduct of sugarcane processing, used as a sweetener, animal feed, or in the production of ethanol.Bagasse: The fibrous residue left after sugarcane crushing, used as fuel or for making paper.中文回答：甘蔗生产工艺。

碳酸盐类矿物

Carbonate Minerals碳酸盐矿物Generally the carbonate minerals are found at or near the surface.They represent the Earth's largest storehouse of carbon（碳的最大储仓）.They all are on the soft side,from hardness3to4on the Mohs hardness scale（莫氏硬度3~4）.Every serious rockhound（矿物学家）and geologist（地质学家）takes a little vial of hydrochloric acid into the field(野外带上一小瓶盐酸),just to deal with the carbonates.The carbonate minerals shown here react differently to hydrochloric acid(下面的碳酸盐矿物与盐酸反应现象不同),as follows:Aragonite bubbles strongly in cold acid文石、霰石在冷盐酸中剧烈气泡Calcite bubbles strongly in cold acid方解石在冷盐酸中剧烈气泡Cerussite does not react(it bubbles in nitric acid)白铅矿在盐酸中不反应，在硝酸中气泡Dolomite bubbles weakly in cold acid,strongly in hot acid白云石在冷盐酸中起点点泡，在热酸中剧烈起泡Magnesite bubbles only in hot acid菱镁矿、海泡石只在热盐酸中起泡Malachite bubbles strongly in cold acid孔雀石在冷盐酸中剧烈起泡Rhodochrosite bubbles weakly in cold acid,strongly in hot acid菱锰矿在冷盐酸中起点点泡，在热酸中剧烈起泡Siderite bubbles only in hot acid菱铁矿只在热盐酸中起泡Smithsonite bubbles only in hot acid菱锌矿只在热盐酸中起泡Witherite bubbles strongly in cold acid碳钡矿、毒重石在冷盐酸中剧烈气泡碳酸盐是由一种或多种金属或半金属元素与碳酸根（CO3）2-结合而成的化合物。

扫描电镜及透射电镜在聚合物研究中应用

碳纳米管的制备
• 电弧放电法 • 激光法 • 化学气相沉积法（CVD） • 流化床反应器
碳纳米管的独特性能
• 纳米尺寸的微结构 • 超高的力学性能 • 特殊的电学性质 • 热稳定性
复合材料理想的填充物
超高的力学性能
Materials
Steel Diamond Carbon Fibers CNTs
Introduction
甲壳素是一种丰富的天然生物有机高聚物。壳聚糖是一种甲壳素脱乙酰基后的产物。化学名
为β-1，4，2-氨基-2-脱氧-D-葡萄糖，是由
大部分的D-氨基葡萄糖和少量的N-乙酰-D-氨
基葡萄糖，以β-1，4糖苷键连起来的直链多糖。
Experimental Section
Preparation of Materials Chitosan of high molecular weight (Mv average molecular weight =182 500 g·mol-1) MWNTs (CVD): Co-Mo/MgO catalysts
Highlighted by Materials Today as a Research News: Materials Today, 2004, 7(4), p.9. Title: “Blending Provides Benefits”
碳纳米管/聚合物复合材料
关键问题碳纳米管在聚合物基体中的分散性和界面黏
在聚合物纳米复合材料研究中的应用
在聚合物/clay纳米复合材料研究中的应用
在聚合物/Carbon nanotubes纳米复合材料研究中的应用
History
1991年，日本电子公司（NEC）的饭岛澄男博士在用电子显微镜观察石墨电极直流放电的产物时，发现一种新的碳结构——碳纳米管（Carbon Nanotubes, CNTs），自此开辟了碳科学发展的新篇章，也把人们带入了纳米科技的新时代。

基于氧化锌锂电池电极材料的优化研究

基于氧化锌锂电池电极材料的优化研究摘要：ZnO具有较高的载流子迁移率、成本低等优点，可以作为电池电极材料。

但研究发现其ZnO基锂离子电池性能不理想，主要问题是电子导电性较低、锂离子扩散速率较慢及LiZn形成使体积膨胀，降低了材料的循环性能和倍率性能。

总结了ZnO基锂离子电池优化方法，如可以通过使用掺杂金属氧化物作为负极材料提升电池容量，改善ZnO结构、添加附着材料及碳包裹技术来改变离子的运动空间及速率从而改善锂电池的充放电速率及性能。

基于以上分析，进一步提出了ZnO基锂离子电子的电池性能改进的可能方案。

关键词：锂离子电池；负极材料；氧化锌；纳米技术前言20世纪70年代以来，锂离子电池作为一种新型储能电池备受关注。

由于其具有高能量、寿命长、低能耗、无公害、无记忆效应以及自放电小、内阻小、性价比高、污染少等优点，锂离子电池在现实应用中显示出巨大的优势，被广泛应用于电动汽车、储能、航天等领域。

锂离子电池主要由正极、负极和电解质溶液等组成。

其中，电极材料是决定锂离子电池的整体性能水平的关键之一。

电解质溶液的性质、组成和浓度则是决定锂离子电池充放电性能的重要因素，对于锂离子电池的制备工艺也起重要的作用。

锂离子电池正极、负极和电解质材料的研究是整个锂离子电池研究领域的重点。

1锂电池发展现状市场上的锂电池绝大部分是LiCoO4做正极材料，石墨碳做负极材料；由于在锂金属沉积/剥离的循环过程中，电沉积控制不佳和体积膨胀，导致锂金属的结构疏松、枝晶生长和“死锂”的产生，同时锂与电解液具有强烈的副反应，导致锂金属的应用一直受到阻碍；在充放电的过程中存在的“穿梭效应”也严重抑制了锂电池的发展。

与此同时，研究发现石墨的理论容量只有375mAh/g，逐渐不能满足当今社会对电池应用的要求，特别是动力能源的高比容量需求。

负极材料主要包括石墨碳、硅的复合物等[1,2,8]。

相比于石墨，ZnO的储存相当丰富，而且具有较高的理论容量（978mA·h/g），被认为是一个有前途的锂离子电池负极材料[10]。

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5,4P S4FL ~,y vL ~ODECOLLECTDR U?PF~ INSULA r[~ SHEEf SEPARATDR
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2.1. Measurements of unit cell performances and lithium diffusion coefficients
The carbon materials are prepared by the pyrolytic treatment of resin at 1100 °C (shows H11 as follows), and of mesophase pitch coal tar at 700 °C ($7) and 3000 °C ($30). The carbon powders were mixed with a solution of 10 wt.% polyvinylidene fluoride (PVDF) dissolved in n-methyl-2pyrrolidine (NMP). The slurry was spread as a thin layer on a copper foil using the doctor blade method. After coating, the electrodes were pressed at 40 k g / c m 2 and at 120 °C. The electrodes were set in polypropylene cells in a parallel plate configuration using lithium foil counter electrode and a lithium reference electrode. The electrolytes were I M LiPF6 dissolved in a 50/50 by volume mixture of ethylene carbonate/methylethyl carbonate ( E C / M E C ) . The cells were discharged by the constant current-constant voltage method (CC--CV). A constant current of 0.5 m A / c m 2 is applied until 0 V versus Li/Li ÷ is reached. Then the constant voltage (0 V) is maintained until 10 ~ A / c m 2 is reached. The cell is then charged to 1.5 V at 0.5 m A / c m 2. The open-circuit voltage (OCV) was measured after 1 h at open-circuit conditions after polarization at 0.1 m A / c m ~.
JOUOHALOI
POWER
E LS E V I E R
Journal of Power Sources 68 (1997) 212-215
lOBES
Low-crystallized carbon materials for lithium-ion secondary batteries
Hayato Higuchi *, Keiichiro Uenae, Akira Kawakami
Fig I Structure of the 18650-type cylindrical LHon battery.
600
.-o- Hll(CCCV) -0- Hll(CC:-0.01Vcut) $7 (CCCV)
--*- S7 (CC: 0.03Vcut)
The lithium diffusion coefficients (DE,) were calculated from the Warburg impedance by potentiostatic a.c. impedance method [9.10]. The impedance measurements carried out under open-circuit conditions in the frequency range from 10~ to 10 2 Hz. The perturbation amplitude was _+5 inV.
Httactu Maxell Ltd., Batter~' R&D Laboratory. 1-1-88, Ushttora, lbaraki, Osaka 567. Japan Accepted 6 November 1996
Abstract
The charge/discharge characteristics and mechanisms of low-crystallized carbons which have larger capacity than graphite have been investigated. Low-crystalhzed carbons have two pnncipal types of charge curve versus Li metal. Hard carbons prepared at 1100 °C (H1 l ) show charge curves with a low average potential, whereas soft carbons pyrolyzed at 700 °C ($7) show those with a high average potential. These results might depend on the lithium diffusion rate in their non-crystallized sites. The 18650-type Li-ion batteries using HI I have comparable capacity versus graphite, whereas the batteries using $7 have low capacity because of their low charge/discharge efficiency. © 1997 Published by Elsevier Science S.A.
2.2. 18650-~pe cylindrical cell
.*g.
400
200
I
I
,
i
Fig. 1 shows the 18650-type cylindrical battery (diameter: 18 mm and height: 65 mm) consisting of a spirally rolled cathode, LiCoO> and an anode inserted in the polyethylene separator. The electrolytes were same as described in Section 2.1. Cell cycling is done by the C C - C V method, in which the constant current is at 1C rate ( 1300 mA) and the constant voltage is maintained at 4.2 V. The cut-off voltage of discharge is 2.75 V (for H I I and $30) or 2.3 V (for $7), respectively.
~ ~'"= 800 1000 mAh/g
1200
Fig. 2. Open-cLrcuitvoltage curves at the first cycle for the H 11, $7 and $30 electrodes.
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Kevwords: Carbon materials; Discharge potential, Lithmm-ton batteries, Lithium diffusion coefficient
1. Introduction
Lithium-ion secondary batteries are currently of interest as high-energy power sources for electronics. Further increase in energy density of these batteries requires increase in specific capacities of the electrode materials. In recent years, carbon-based materials have been extensively studied as the anodes of these batteries. There have been many reports of low-crystallized carbons with capacities greater than that of graphite (CrLi at 372 m A h / g ) [ 1-8]. For example, carbons made by pyrolyzing pitch at 700°C [ 1,2], polyparaphenylene (PPP) [3] and polyacenic semiconductor (PAS) [4] were shown to have capacities of up to 700 mAh/g. Pyrolyzed polyfurfuryl alcohol with capacities near 450 m A h / g have been prepared by Omaru et al. [5 ]. Low-crystallized carbons have been observed to have two types of charge curve versus lithium metal depending on the raw materials used (precursor) and/or the heat-treatment temperature: the first type shows charge curves similar to graphite with a low average potential versus Li/Li +, and the other has charge curves with a high average potential. Each charge potential would be affected by the electrochemical potential of lithium doped in non-crystallized sites in addition to the interlayer. In order to discuss the relationship between the lithium doping/undoping mechanisms for low-crystallized carbons and the charge potential, the lithium diffusion coefficients in each carbon sample was measured.