Investigation of mechanical properties of fractured marbles by uniaxial compression tests

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谢丹：女,汉族,1978年3月生,厦门理工学院机械与汽车

培养方向车辆传动、电控技术及其应用联系方式xiedan@谢丹：女，厦门理工学院机械与汽车工程学院副教授。

2010年6月毕业于华中科技大学机械科学与工程学院机械制造及其自动化（精微制造工程）专业，获工学博士学位。

国家自然科学基金同行评议专家，SCI源刊《Microelectronic Engineering》、《Optical Engineering》审稿人。

研究领域为非传统加工工艺及装备，主要从事微滴喷射、纳米压印及微接触印刷等技术的研发。

主持国家自然科学基金面上项目、国家自然科学基金青年基金、福建省自然科学基金、厦门市科技计划各1项，参与国家自然科学基金重点项目1项、面上项目1项、国家科技重大专项项目1项、高等学校博士点专项科研基金资助项目1项。

曾参与研制纳米压印机、高效微电火花加工机床、机械式喷胶设备、气动膜片式微喷射设备、压电式三维打印系统及滚筒式微接触印刷装置等。

先后在《Optics Express》、《Science China Technological Sciences》、《中国科学：技术科学》等期刊等国内外权威期刊发表论文10余篇（第一或通讯作者），其中SCI检索3篇，EI检索4篇，申请（授权）专利9项。

期刊论文（*通讯作者）[1]Dan Xie*, Honghai Zhang, Xiayun Shu, Junfeng Xiao. Fabrication of polymer micro-lens array withpneumatically diaphragm-driven drop-on-demand inkjet technology. Optics Express.20(14):15186-15195,2012 (SCI/EI, IF=3.587)[2]Xie Dan*,Zhang Honghai,Shu Xiayun,Xiao Junfeng,Cao Shu. Multi-materials drop-on-demand inkjettechnology based on pneumatic diaphragm actuator.Science China Technological Sciences.53(6):1605-1611,2010 (SCI/EI)[3]Xuefeng Chang, Xie Dan*. Noncontact Microembossing Technology for Fabricating Thermoplastic OpticalPolymer Microlens Array Sheets. Scientific World Journal, V olume 2014 ,(8)（SCI/EI,IF=1.29）[4]谢丹*,张鸿海,舒霞云,肖峻峰,曹澍.气动膜片式多材料微液滴按需喷射技术研究.中国科学：技术科学.40(7):794-801,2010[5]谢丹*,张鸿海,舒霞云等. 气动膜片式微滴喷射装置理论分析与实验研究. 中国机械工程.23(14):1732-1737,2012[6]谢丹*,张鸿海,陶晟等. PMMA微透镜阵列的非接触式热压印制作技术. 机械科学与技术.31(12):1955-1958,2012[7]Dan Xie*, Honghai Zhang, Sheng Liu.Mechanical Properties Investigation of PMMA PC and PS during ThermalNanoimprinting. The fourth International Symposium on Precision Mechanical Measurements 2008,（EI）[8]张鸿海,谢丹,刘胜等.基于荷花效应的双微观超疏水表面制作技术研究.中国机械工程.20(2):207-210,2009[9]王迎春,谢丹,张鸿海.基于非接触式热压印技术的微透镜阵列制作.机电工程. 27(11):13-16,2010[10]Shu Xiayun,Zhang Honghai,Liu Huayong,Xie Dan.Experimental study on high viscosity fluid micro-droplet jetting system.Science China Technological Sciences. 53(1):182-187,2010 (SCI/EI)[11]舒霞云,张鸿海,刘华勇, 谢丹.高黏度微量喷射系统的实验研究.中国科学：技术科学.40(2): 171-176,2010[12]舒霞云,张鸿海,张丰,谢丹.用于微喷嘴制作的高效微电火花加工技术.华中科技大学学报(自然科学版). 38(2):48-51, 2010[13]张鸿海,舒霞云,肖峻峰,谢丹.气动膜片式微滴喷射系统原理与实验.华中科技大学学报(自然科学版). 37(12):100-103,2009申请（授权）专利[1]微透镜阵列模具的制作方法，2013.7，申请号：201310292971.3（第一）[2]一种半球透镜模具的制作方法，2014.7，申请号：201410334276.3（第一）[3]一种基于音圈电机的微接触印刷装置及其工作流程，2013.10，申请号：201310501232.0（第二）[4]一种基于音圈电机的微接触印刷装置，2013.10，授权号：ZL201320654416.6（第二）[5]一种立式金刚石串珠绳锯机，2013.10，授权号：ZL201320730095.3（第二）[6]一种卧式微电火花机床及应用该机床进行在线加工的方法，2012.01，授权号：ZL201010502952.5（第三）[7]块状石材全自动磨抛机及其控制方法，2014.2，申请号：201410047484.5（第三）[8]块状石材全自动磨抛机，2014.2，申请号201420061641.3（第三）[9]一种气动膜片式微滴喷射方法及装置，2011.01，授权号：ZL200910305515.1（第四）科研项目（在研）[1]国家自然科学基金面上项目：基于热释电效应的碳基电子器件微纳复合喷射印刷机理与关键技术研究/51475400，起止时间：2015.01-2018.12（主持）[2]国家自然科学基金青年基金：有机电子薄膜连续式微接触图形化印刷原理与工艺研究/51105321，起止时间：2012.01-2014.12（主持）[3]福建省自然科学基金：仿生平面复眼透镜的非接触式可控压印制作技术研究/2013J05084，起止时间：2013.01-2015.12（主持）[4]厦门市科技计划项目：LED聚合物微透镜阵列的微滴喷射制作技术研究与开发/3502Z20113036，起止时间：2010.10-2013.12（主持）[5]福建省自然科学基金：非回转对称表面加工快刀伺服系统关键技术研究/2012J01237，起止时间：2012.01-2014.12（参与）[6]企业委托项目：一种异型石材外形检测识别及自动化图形编程系统开发/ HJ13010，起止时间：2013.09-2015.08（参与）。

mechanical properties

工艺性能不属于 “ 力学性能 ” 是周知的共识，而实际上ＭＰ包括工艺性能，如弯曲、压扁、顶锻和成形性等等，更包括液压和润滑性能。力学中的力具有三要素，而这些性能（包括伸长率）试验绝大多数始终都与力的大小无关。ＭＰ中的顶锻等试验，可由用户根据是否出现裂纹、裂纹的性
一
３． “ 力学性能 ”用词是否正确怀疑 “ 力学性能 ”是否正确的理由如下：
（１）并不存在 “ 力学性能 ” 。材料具有物理和化学性能，但力学是研究物体运动规律的，力学有原理、定律、判据和行为，也可以称自由落体具有力学的性质，但并不研究物体本身的性能，
例如并没有 “ 牛顿力学性能 ” 。材料力学研究构件在外力作用下的变形、破坏或失效的规律。既是研究 “ 规律 ” ，就无 “ 规律 ” 的性能，即并不
ＭＰ的定义就是机械性能１．ＭＰ在广义上的含义是机械性能
一
要观点摘录如下：
对于金属材料的重要术语ｍｅｃｈａｎｉＣａ１ｐｒｏｐｅｒｔｉｅｓ（以下简称ＭＰ），２０世纪８Ｏ年代前中国大陆称为 “机械性能 ” ，以后改称为 “力学性能 ” ，并成了固定的术语。笔者认为 “力学性能 ”的译法并不合适，阐明了ＭＰ正确的定名应是国际通用、概念确切的 “ 机械性能 ” ，并认为所谓的 “ 力学性能 ”并不存在。

水泥搅拌桩试验方案

水泥搅拌桩试验方案1. 引言水泥搅拌桩是一种常用的地基处理技术，广泛应用于建筑工程、桥梁工程以及沿海、沿江、沿湖等地区的防护工程中。

本试验方案旨在详细介绍水泥搅拌桩试验的目的、试验方法、试验过程和数据分析等内容，以确保试验质量和工程效果。

2. 试验目的本试验旨在通过对水泥搅拌桩试验的详细记录和数据分析，评估其在工程中的可行性和效果，从而为实际工程提供参考依据。

试验目标包括但不限于以下几个方面： - 评估水泥搅拌桩在地基处理中的强度增加效果； - 评估水泥搅拌桩的稳定性和变形特性； - 评估水泥搅拌桩与周围土体的界面特性； - 提供水泥搅拌桩施工参数的优化建议。

3. 试验方法本试验采用以下方法进行： ### 3.1 试验准备首先，确定试验桩的尺寸和布置方案，并进行试验场地的准备工作。

选取适当位置进行水泥搅拌桩的试验施工，保证试验桩布设的均匀性和代表性。

3.2 试验设备与仪器本试验需要准备以下设备与仪器： - 搅拌桩机：用于搅拌水泥浆和土壤，形成水泥搅拌桩； - 钻孔设备：用于钻孔并确定桩的位置； - 馈浆设备：用于提供混合材料（水泥、水和骨料等）； - 静力触探设备：用于评估桩的承载力和变形特性等；- 环境监测仪器：用于监测试验现场的温湿度、沉降等环境指标。

3.3 试验过程本试验需要按照以下步骤进行： 1. 钻孔：按照设计要求进行钻孔，确定桩的位置和布设方案； 2. 搅拌桩施工：搅拌桩机进行水泥浆和土壤的搅拌，在钻孔处形成水泥桩体； 3. 复合地基处理：将水泥搅拌桩与周围地基进行复合处理，提高整体地基的承载力和稳定性； 4. 牵引静力触探试验：在试验桩周围进行静力触探试验，评估桩的力学特性和承载力； 5. 环境监测：对试验现场的温湿度、沉降等环境因素进行监测； 6. 数据记录与分析：将试验过程中的数据进行记录，并进行数据分析和评估。

3.4 数据分析通过试验数据的分析和评估，可以得出水泥搅拌桩的力学性能和工程效果，为实际工程提供参考依据。

专业英语材料机械性能

专业英语材料机械性能材料机械性能机械专业英语机械专业英语词汇机械工程专业英语机械专业英语翻译机械专业英语文章机械制造专业英语材料专业英语机械专业英语词典
Preface
The goal of the following pages :
To characterize materials in terms of some of the
The result of a tensile test is commonly displayed in a stress–strain diagram( 应力 - 应变图 ). Several important characteristics are immediately evident. During the initial stress period, the elongation of the material responds to in a linear fashion; the rod reverts back to its original length upon relief of the load(卸载). This region is called the elastic range. Once the stress exceeds, however, a critical value, called the yield strength(屈服强度), some of the deformation of the material becomes permanent.

The tensile test and the resulting stress–strain diagrams have been shown above to provide a comprehensive insight into many of the mechanical properties of materials. For specialized applications, however, a handful of further tests are commonly used.

Microstructure and mechanical properties

Microstructure and mechanical properties of ZrB 2–SiC nanocomposite ceramicQiang Liu,*Wenbo Han and Ping HuCenter for Composite Materials,Harbin Institute of Technology,Harbin 150001,ChinaReceived 28March 2009;accepted 30May 2009Available online 6June 2009A ZrB 2–SiC nanocomposite ceramic in which 20vol.%nanosized SiC powder was introduced into a ZrB 2matrix was fabricated by hot-pressing at 1900°C for 60min under a 30MPa uniaxed load.The composite microstructure showed intragranular nanostruc-tures that were peculiar to this material.Investigation of the mechanical properties revealed a ﬂexural strength of 930±28MPa and a fracture toughness of 6.5±0.3MPa m 1/2.These improved mechanical properties were strongly dependent on the formation of the unusual intragranular nanostructures.Ó2009Acta Materialia Inc.Published by Elsevier Ltd.All rights reserved.Keywords:Intragranular nanostructure;Mechanical properties;Microstructure;Fracture toughness;NanocompositeUltrahigh-temperature ceramics (UHTCs),suchas borides and carbides,were developed in the 1960s [1].Among UHTCs,zirconium diboride (ZrB 2)is a material of particular interest because of its excellent combination of high melting point,low theoretical den-sity,high electrical conductivity,good chemical inert-ness and superb wear resistance.These properties make it an attractive candidate for high-temperature applications such as refractory materials in foundries,electrical devices,nozzles and armor [2].Moreover,ZrB 2could be used for super-high-temperature struc-tural applications in aerospace [3,4].Its low mechanical properties,however,have long prevented this material from being used in a wide range of applications.Its sus-ceptibility to brittle fracture can lead to unexpected cat-astrophic failure,therefore its mechanical properties must be improved before the potential applications of ZrB 2can be fully realized.The introduction of a second phase of particles has been a successful strategy for improving the mechanical properties of monolithic diboride ceramics.With this aim,introduction of SiC particles [3–6]into ZrB 2yields a ZrB 2–SiC composite ceramic that is far stronger than monolithic ZrB 2.As a rule,however,improvement of mechanical properties is limited by the micro-sized par-ticles of the second phase.The mechanical properties of ceramics can be signif-icantly improved by introducing nanosized ceramic par-ticles into the ceramic-matrix grains or grain boundaries.The most signiﬁcant achievements with this approach have been reported by Niihara and Nakahira [7–9],who ﬁrst revealed that an introduction of 5vol.%of nanosized SiC particles into Al 2O 3increased the room-temperature strength of the composite from 350MPa to $1.0GPa (three-point ﬂexure,30mm span).Similar improvements in strength have since been achieved in Al 2O 3–Si 3N 4,MgO–SiC and Si 3N 4–SiC composite systems.Materials constructed by these types of approaches are termed nanocomposite ceramics.At this point in time,however,there have been few attempts to create nanocomposite ceramics out of ZrB 2–SiC.Moreover,the eﬀects of the composite micro-structure on the mechanical properties of ZrB 2–SiC nanocomposite ceramics have never been documented.Therefore,the aim of the present study was to investi-gate the microstructural features and eﬀects on mechan-ical properties of a ZrB 2–SiC nanocomposite ceramic.The starting powders used in this study were:ZrB 2powder (Northwest Institute for Non-ferrous Metal Re-search,China),average particle size 2l m (>99%);and nanosized b -SiC powder (Kaier Nanotechnology Devel-opment Co.Ltd,China),average particle size 30nm (>98%).The nanosized SiC powder was ﬁrst dispersed in ethanol,with 1h of ultrasonication.Then the powder mixture ZrB 2plus 20vol.%nanosized SiC particles were ball-milled using ZrO 2ball media and ethanol at1359-6462/$-see front matter Ó2009Acta Materialia Inc.Published by Elsevier Ltd.All rights reserved.doi:10.1016/j.scriptamat.2009.05.041*Corresponding author.Tel./fax:+8645186402382;e-mail:dqz0402@Available online at Scripta Materialia 61(2009)690–692/locate/scriptamat180rpm for 12h.All ball-milling was performed in polyethylene bottles.After mixing,the resulting slurry was dried by rotary evaporation and then screened.The obtained powder mixtures were hot-pressed at 1900°C for 60min at a uniaxial pressure of 30MPa in Ar atmosphere.The microstructure of hot-pressed specimens was ob-served by using scanning electron microscopy (SEM,FEI Sirion,Holland)and transmission electron micros-copy (TEM,Hitachi H-9000,Japan)with an X-ray en-ergy dispersive spectroscopy (EDS,EDAX Inc.)analyzer attachment.Flexural strength (r )was tested in three-point bending on 3Â4Â36mm bars,using a 30-mm span and a crosshead speed of 0.5mm min À1.Each specimen was ground and polished with diamond slurries to a 1-l m ﬁnish.The edges of all the specimens were chamfered to minimize the eﬀect of stress concen-tration resulting from machining ﬂaws.Fracture tough-ness (K IC )was evaluated by a single-edge notched-beam test with a 16-mm span and a crosshead speed of 0.05mm min À1using 2Â4Â22mm test bars on the same jig used for the ﬂexural strength.All ﬂexural bars were fabricated with the tensile surface perpendicular to the hot-pressing direction.A minimum of ﬁve specimens was tested in each experimental condition.Figure 1shows the typical microstructural morphol-ogies of the ZrB 2–SiC nanocomposite ceramic under SEM (Fig.1a)and TEM (Fig.1b).As shown in Figure 1a,a number of submicron SiC particles (dark contrast)are located along the grain boundaries of the ZrB 2(gray contrast).Some smaller SiC particles also appear inside the ZrB 2grains (indicated by arrows);these are termed intragranular nanostructures.Higher magniﬁcation examination of the ZrB 2–SiC nanocomposite ceramic by TEM (Fig.1b)showed that the intragranular SiC particles (indicated by arrows)were approximately 100nm in size.The formation of the intragranular nanostructures was dependent on both the migration speed of ZrB 2ma-trix grain boundary and the migration speed of the SiC second phase [10,11].When the migration speed of the second phase was less than that of the matrix grain boundary,the nanosized SiC particles tended to be trapped within the ZrB 2grains during sintering.The ﬁne ZrB 2particles would then coalesce around them,form-ing the intragranular nanostructures.Figure 2shows that the specimen fracture surface used for testing fracture toughness exhibited the typicalcharacteristics of a transgranular fracture.In monolithic ZrB 2ceramic,the predominant fracture mode would have been intergranular [12].There are two possible interpretations for this diﬀerence in fracture mode.The ﬁrst is that the intergranular SiC particles in the ZrB 2–SiC nanocomposite ceramic were ﬁrmly bonded to the ZrB 2/ZrB 2interfaces.This rigid bonding could then have suppressed intergranular fracture [13].The other explanation is that there are diﬀerences in relaxation of the tensile residual stress around the SiC particles located between the intergranular and intra-granular.Because of the diﬀerent thermal expansion coeﬃcients between SiC and ZrB 2,a large internal stress will be generated during cooling after sintering.Assum-ing that a SiC particle is spherical,an internal tension will occur in a tangential direction to the ZrB 2matrix around the SiC particle.This will cause a crack to al-ways propagate towards the SiC particle.The internal tangential tension also would be relaxed by lattice and grain-boundary diﬀusion around the intragranular and intergranular particles,respectively.However,the tem-perature at which the grain-boundary diﬀusion is acti-vated would be lower than that required by lattice diﬀusion,thus the internal tangential tension around the intergranular SiC particles would be further relaxed during cooling.As a result,the internal tangential ten-sion around the intragranular SiC particles of the sin-tered body would always be greater than that around the intergranular particles.This would lead to a fracture surface that would always tend to be characteristic of a transgranular fracture.Thus,it is the intragranular nanostructures that predominantly induce the trans-granular fracture characteristic of the ZrB 2–SiC nano-composite ceramic.Examination of the mechanical properties of the ZrB 2–SiC nanocomposite ceramic revealed a fracture toughness that ranged from 6.4to 6.7MPa m 1/2.This represented an increase of approximately 83%over that of the monolithic ZrB 2(2.3–3.5MPa m 1/2)[2].In addi-tion,the ﬂexural strength (920–945MPa)of this nano-composite ceramic was also signiﬁcantly higher than that recently reported for the monolithic ZrB 2($565MPa)[4].The formation of the intragranular nanostructures appeared to play an important role in the improved mechanical properties of the ZrB 2–SiC nanocomposite ceramic,especially its increased fracture toughness and ﬂexural strength.In order to investigate eﬀects of the intragranular nanostructures on the mechanical properties oftheFigure 1.Typical microstructural morphologies of the ZrB 2–SiC nanocomposite ceramic:(a)SEM image of the sample and (b)TEM image of thesample.Figure 2.SEM image of the fracture surface of the ZrB 2–SiC nanocomposite ceramic.Q.Liu et al./Scripta Materialia 61(2009)690–692691ZrB 2–SiC nanocomposite ceramic,it is necessary to investigate a crack propagation behavior in this mate-rial.Figure 3shows TEM micrographs of crack propa-gation behavior in the ZrB 2–SiC nanocomposite ceramic.It was evident that the crack had never propa-gated in a straight line,but had been deﬂected,selecting the neighboring particles (Fig.3a).As stated previously,this deﬂection was caused by thermal internal stress in this material.It can be also seen in Figure 3a that a crack has penetrated through an intragranular particle (indicated by black arrow).The possible reason for this case is that the cracked particle may be an agglomera-tion composed of many ﬁne SiC particles.Because the bond strength of this agglomeration is not high enough,it tends to fracture when a crack meets this kind of par-ticle.However,for other intragranular particles (<100nm),neither crack penetration through the intra-granular particles nor propagation along the particle/matrix interfaces was evident (Fig.3b).This phenome-non indicates that the intragranular particles bridged the crack,pointing to the existence of a particle-bridging mechanism.Based on the experimental observation above,a spe-ciﬁc explanation for this eﬀect is as follows.When a pri-mary crack meets an intragranular nanosized SiC particle,it is normally impeded and thus bows (Fig.3a).The bowing crack bypasses the impenetrable particles and instead interacts with neighboring cracks.At this point,the bridging particles ﬁrmly pin the cracks and further prevent the crack from extending.As a re-sult,only by increasing the crack extension force can the crack further extend.In other words,it is by means of the particle-bridging mechanism that the strength and toughness of the ZrB 2nanocomposite ceramic are signif-icantly improved.Besides the explanation mentioned above,there is an-other one for the improvement in strength.After the for-mation of the intragranular nanostructures,there are many sub-interfaces within the ZrB 2matrix grains that belong to the interfaces between intragranular particles and matrix grains.As stated previously,moreover,be-cause of the diﬀerence in thermal expansion coeﬃcients between the ZrB 2matrix and the SiC second phase,a large number of microcracks were formed around the intragranular particles,as shown in Figure 4.The for-mation of the sub-interfaces and microcracks can cause the matrix grains to be at a potential diﬀerentiation state,corresponding to the further grain reﬁning.Thisthen improves the strength of this material according to the Hall–Petch equation [10].As discussed above,it is concluded that the formation of intragranular nanostructure is the fundamental rea-son for the signiﬁcant increase in the mechanical proper-ties of this nanocomposite ceramic.In conclusion,a hot-pressed ZrB 2–SiC nanocompos-ite ceramic was fabricated by introducing nanosized SiC powder into a ZrB 2matrix.the intragranular nanostruc-tures were peculiar to this ceramic-based composite and induced a transgranular fracture characteristic.The mechanical properties of this nanocomposite ceramic,especially its ﬂexural strength and fracture toughness,were much higher than those of monolithic ZrB 2.It is believed that the formation of intragranular nanostructures is a main reason for the improvements in mechanical properties of the ZrB 2–SiC nanocompos-ite ceramic.Intragranular particle bridging is believed to be the predominant toughening mechanism imparting the improved characteristics to this material.This work was supported by the NSFC(10725207),the Research Fund for the Doctoral Pro-gram of Higher Education (24403037)and National Natural Science Fund for Outstanding Youths (24402052).[1]E.V.Clougherty,R.L.Pober,L.Kaufman,Trans.Met.Soc.AIME 242(1968)1077.[2]F.Monteverde,S.Guicciardi,A.Bellosi,Mater.Sci.Eng.A 346(2003)310.[3]A.L.Chamberlain,W.G.Fahrenholtz,G.E.Hilmas,D.T.Ellerby,J.Am.Ceram.Soc.87(2004)170.[4]F.Monteverde,C.Melandri,S.Gicciardi,Mater.Chem.Phys.100(2006)513.[5]F.Monteverde,Appl.Phys.A 82(2006)329.[6]S.S.Hwang,A.L.Vasiliev,N.P.Padture,Mater.Sci.Eng.A 464(2007)216.[7]K.Niihara, A.Nakahira,in:P.Vincentini (Ed.),Advanced Structural Inorganic Composites,Elsevier Sci-ence Publishers,Trieste,Italy,1990,pp.637–664.[8]K.Niihara,A.Nakahira,Ann.Chim.16(1991)479.[9]K.Niihara,J.Ceram.Soc.Jpn.99(1991)974.[10]W.D.Kingery,H.K.Bowen,D.R.Uhlmann,Introduc-tion to Ceramics,Wiley,1976.[11]C.M.Wang,J.Mater.Sci.30(1995)3222.[12]S.Q.Guo,J.M.Yang,H.Tanaka,Y.Kagawa,Compos.Sci.Technol.68(2008)3033.[13]I.A.Ovid’ko,A.G.Sheinerman,Scripta Mater.60(2009)627.Figure 3.TEM micrographs of crack propagation behavior in the ZrB 2–SiC nanocomposite ceramic:crack propagation is from upper right to lowerleft.Figure 4.TEM micrograph of microcracks around an intragranular particle.692Q.Liu et al./Scripta Materialia 61(2009)690–692。

mechanical properties中文名演变过程及定义

mechanical properties中文名演变过程及定义作者：赵中平等来源：《中国科技术语》2015年第01期摘要：文章阐述了mechanical properties中译名由“机械性能”到“力学性能”的演变过程，认为mechanical properties译为“力学性能”并不合适，应译为“机械性能”。

指出了这种变更存在的问题，进一步说明了mechanical properties一词的定义。

关键词：术语，金属材料，机械性能，力学性能中图分类号：N04；H059；TH文献标识码：A文章编号：1673-8578（2015）01-0042-05Abstract： This article mainly elaborates the evolution process of the Chinese translation on “mechanical properties”. The author points out that “lixue xingnen” is not suitable for the Chinese tran slation of “mechanical properties”， and further illustrate that the definition on the term “mechanical properties”.Keywords： term，metal material，mechanical properties对于金属材料的重要的术语mechanical properties（以下简称MP），20世纪80年代前中国大陆称为“机械性能”，以后改称为“力学性能”，并成了固定的术语。

在资料[1]～[4]中，笔者认为“力学性能”的译法并不合适，阐明了MP正确的定名应是国际通用、概念确切的“机械性能”，并认为所谓的“力学性能”并不存在。

下面通过历史回顾和事实分析，叙述“机械性能”怎样被引导成“力学性能”，指出MP等同于“力学性能”的观点是由不恰当的翻译形成的误解，进一步阐明MP的定义就是“机械性能”。

探索人体机械运动规律及其与体育运动技术关系的学科。

The discipline that explores the mechanical principles of human body movement and its relationship to sports performance is called biomechanics. Biomechanics combines principles from physics, engineering, and biology to understand how forces and motion interact within the human body during different physical activities.人体机械运动规律及其与体育运动技术关系的学科被称为生物力学。

生物力学结合了物理、工程和生物学原理，以了解人体在不同体育活动中的内部力和运动如何相互作用。

Biomechanics seeks to understand the underlying mechanisms that enable humans to perform complex movements efficiently and safely. By studying factors such as joint angles,muscle activation patterns, and external forces acting on the body, biomechanics researchers can identify optimal movement patterns for specific sports techniques.生物力学旨在了解人类如何以高效安全的方式进行复杂运动的基本机制。

通过研究关节角度、肌肉激活模式以及对身体施加的外部力等因素，生物力学研究人员可以确定特定体育技术的最佳运动模式。

低温条件下QTD9008的力学性能研究

低温条件下QTD900-8的力学性能研究郑言彪，张军(湖北省机电研究设计院股份公司，湖北武汉430070)摘要:以2TD900-8材料为研究对象，采用拉伸、冲击、布氏硬度测试以及扫描电镜的分析方法，研究其在低温条件下的断，：（1)1 的，QTD900-8的化大，-60#，对于强高了19.8%，33.0%，韧 70E，高了18.4%;(2)的，QTD900-8发生了韧性断断断化的；（3> ，断墨产生，面，材料断。

关键词:ADI;1中图分类号:TG255 文献标识码：B 文章编号：1003-8345(2019)01-0005-04D0I：10.3969/j.issn.1003-8345.2019.01.002Investigation on Mechanical Properties of QTD900-8 under Low Temperature ConditionZHENG Yan-biao, ZHANG Jun(Hubei Mechanical and Electrical Research and Design Institute Co.,Ltd.，Wuhan 430070,China) Abstract:By using QTD900-8 material as investigation object，adopting tensile test，impact test，HB test and SEM analysis，the mechanical properties，fracture morphology characteristics of the material were investigated，the result showed: (1)With the decrease of temperature，the mechanical properties of QTD900-8 vary greatly:compared with normal temperature condition，at -60 +，the tensile strength was increased by 19.8%，the elongation decreased by 33.0%，the impact toughness decreased by more than 70%，the hardness elevated by 18.4%. (2)As the temperature drops，the process of ductile fracture，mixed mode fracture and brittle fracture occurred with QTD900-8. (3)At low temperature，cracks first occur in graphite in the process of tensile fracture，and then spread to the whole section，which led to the fracture of the material.Key words:ADI; low temperature; mechanical properties等球墨铸铁(ADI)的，工机磨等面广应用，是对其的研究。

机械英语知识点总结大全

机械英语知识点总结大全一、Basic Mechanical Engineering 基本机械工程1. Mechanical Engineering 机械工程Mechanical engineering is the branch of engineering that involves the design, production, and operation of machinery. 机械工程是涉及机械设计、生产和操作的工程分支。

2. Force and Motion 力和运动Force is any interaction that, when unopposed, will change the motion of an object. 力是任何相互作用，当没有阻力时，会改变物体的运动。

3. Simple Machines 简单机械A simple machine is a mechanical device that changes the direction or magnitude of a force. 简单机械是一种可以改变力的方向或大小的机械设备。

4. Kinematics 运动学Kinematics is the branch of classical mechanics that describes the motion of points, bodies, and systems of bodies without considering the forces that cause the motion. 运动学是描述点、物体和物体系统运动的经典力学分支，不考虑引起运动的力。

5. Dynamics 动力学Dynamics is the study of forces and torques and their effect on motion. 动力学是力和转矩以及它们对运动的影响的研究。

竹-地聚物复合材料的初步研究英语

竹-地聚物复合材料的初步研究英语## A Preliminary Investigation of Bamboo-Based Polymeric Composites.Bamboo-based polymeric composites (BBPCs) are a class of materials that are composed of bamboo fibers and a polymer matrix. These materials have the potential to offer a number of advantages over traditional materials,including high strength, low weight, and biodegradability.In this study, we investigated the mechanical properties of BBPCs that were fabricated using different types of bamboo fibers and polymer matrices. We found that the mechanical properties of the BBPCs were significantly influenced by the type of bamboo fiber and polymer matrix used. The BBPCs that were fabricated using bamboo fibers that had been treated with a silane coupling agent exhibited the highest mechanical strength.The results of this study suggest that BBPCs have thepotential to be used as a sustainable alternative to traditional materials in a variety of applications,including automotive, construction, and furniture.## 竹基聚合物复合材料的初步研究。

ADI材料在防护支座产品上的开发应用

Nodular IronADI材料在防护支座产品上的开发应用高峰，曾圣湖，武炳煥(东风商用车有限公司铸造二厂，湖北十堰442013)摘要:介绍了近年来公司ADI铸件的产量及产品结构变化，详细阐述了 ADI防护支座的开发应用过程。

通过使用QTD900-8材料替代ZGD650-830材料，实现了 ADI在防护支座类铸件上的批量生产应用，达到了铸件的轻量化和降低生产成本的目标，最后得出以下结论:（1)使用ADI材料替代铸钢件，可以实现铸件的轻量化;（2)生产ADI的产品要控使用材料量量，出现材料质量的发生；（3)在量要求的下，尽量使用高牌号的ADI，以实现铸件质量更轻、成本更低的目标;（4)ADI产品的成和铸件的结构直，结构、铸件量的件生产成低关键词:ADI;防护支座;轻量化;成本中图分类号:T0255 文献标识码:A 文章编号：1003-8345(2019)01-0001-05D01:10.3969/j.issn.1003-8345.2019.01.001Development and Application of ADI Material in Protective Support ProductsGAO Feng,ZENG Sheng-hu,WU Bing-huan(No.2 Foundry，Dongfeng Commercial Vehicle Co.,Ltd.，Shiyan 442013,China)Abstract:The output and product structure change of ADI castings in recent years were introduced. The development and application process of ADI protective support was described in detail. By using QDT900-8 instead of ZGD650-830,the application of ADI in batch production of protective supporter castings was realized，the aim of lightening casting and reducing production cost had been achieved. Finally，the following conclusions were drawn:(1)Using ADI material to replace steel castings could realize the lightening of castings. (2)For the production of ADI products，it was needed to control the trace elements of raw materials to avoid the occurrence of material quality was not up to standard. (3)Under the condition of satisfyingthe quality requirement，the higher grade ADI should be used as far as possible to achieve the goal of lighter casting qualityand lower cost. (4 )The cost of ADI products was directly related to the structure of castings，the cost of castings with small spatial structure and heavy mass was relatively low.Key words:ADI;protective support;light weight;cost公司在ADI材料的应用上了量的研发，开要应用产品，得了的成，在轻铸件量上十近年来，在商用上应用，要用ADI件的，应用座、类产品，产量一直。

江汉盆地黄场盐穴地下储气库储气性评价

江汉盆地黄场盐穴地下储气库储气性评价付晓飞【期刊名称】《《广东石油化工学院学报》》【年(卷),期】2019(029)006【总页数】4页(P16-18,29)【关键词】盐穴地下储气库; 储气性评价; 区域构造特征; 气密性试验【作者】付晓飞【作者单位】中国石化江汉油田分公司勘探开发研究院湖北武汉430223【正文语种】中文【中图分类】TE822近年在全国多地出现的“气荒”，凸显了天然气调峰保供的紧迫性，促进了地下储气库建设。

盐岩以其良好的蠕变特性、低渗透率以及力学性能，被公认为能源储存的理想介质[1-4]。

盐穴储气库是利用地下较厚的盐岩或盐丘，建造洞穴形成储集空间来存储天然气[5]。

盐穴储气库与其他类型的储气库相比，具有构造完整、夹层少、厚度大、物性好、非渗透性好、可缩性强、密封性好、易开采等优点。

江汉盆地黄场地区位于湖北省潜江市，紧邻江汉油田盐化工总厂，毗邻武汉、荆州等市，大中型企业密布，能源缺乏，天然气市场广阔，同时具有丰富的盐矿资源。

川气东送管道、新气管道在潜江互通，在此建设储气库可同时解决两条大型输气干管的季节调峰、应急调峰需求，可极大提高储气库的利用效率。

盐穴储气库的运营对周围人民的生命财产安全至关重要，因此，开展储气性评价具有深远战略意义。

1 建库基本条件盐穴储气库存选址要遵循以下几条原则[6-8]：(1)盐层厚度大,无断层影响；(2)盐层品位高,有利造腔；(3)顶板强度大,有利气库安全；(4)盐层内部夹层少、厚度小,有利造腔；(5)埋深大于400 m,保证一定储气能力；(6)水源充足,保证造腔用水。

黄场地区基本具备了以上几个建库条件。

2 区域构造特征黄场地区位于江汉盆地中部，面积2610 km2，由长期继承性发育的双断箕状断陷发育而成，是潜江组沉积时期的成盐中心。

该地区具有南浅北深，中间稍高的特点，其西北边受北东—北北东向的潜北断层控制，东南边受北东—北北东向的通海口断层控制，东北边为沉湖低凸起，西南边为丫角新沟低凸起。

ta9钛钯合金成分

ta9钛钯合金成分钛钯合金是一种重要的高温合金材料，由钛和钯两种金属元素组成。

钛属于过渡金属，化学符号为Ti，原子序数为22，原子量为47.87。

钯则是一种银白色贵金属，化学符号为Pd，原子序数为46，原子量为106.42。

钛钯合金以其卓越的耐热性、耐腐蚀性和高强度特性广泛应用于航空航天、化工、医疗器械等领域。

钛钯合金的成分主要取决于所需的性能和用途。

一般来说，钛钯合金的钯含量在1%到30%之间，钛含量则占剩余百分比。

此外，钛钯合金还可以添加其他元素来改善其性能。

一种常见的钛钯合金是Ti-Pd。

钯在Ti-Pd合金中起到了晶界强化和防止晶粒长大的作用。

研究表明，含有不同钯含量的Ti-Pd合金其晶粒尺寸和力学性能存在一定关系。

通过控制钯含量，可以调制合金的微观结构和宏观性能。

除了钯，还可以添加其他元素来改变钛钯合金的性能。

例如，添加铝（Al）的钛钯合金可以提高其机械强度和耐热性能；添加铜（Cu）可以增强其耐腐蚀性；而添加银（Ag）则可以提高其导电性能。

此外，钛钯合金还可以进行热处理来改善其性能。

热处理可以通过固溶处理和时效处理来控制合金的晶粒尺寸和相组成，从而改变其硬度、强度和耐腐蚀性能。

研究人员还发现，热处理可以提高钛钯合金的疲劳寿命和耐磨性能。

总之，钛钯合金的成分可以通过调整钯含量和添加其他元素来实现。

这些变化可以改变合金的微观和宏观性能，满足不同领域对钛钯合金的需求。

钛钯合金的研究和应用具有重要意义，对于提高材料性能和推动相关领域的发展具有积极的影响。

参考文献：1. Li, G., et al. "Effects of Pd content and thermal aging on microstructural stability and mechanical properties of a near-α titanium alloy." Journal of Alloys and Compounds 792 (2019): 577-586.2. Sun, C., et al. "Microstructure and mechanical properties of Ti–Pd alloys with different Pd contents." Acta Materialia 80 (2014): 458-468.3. Lin, J., et al. "Effect of microstructure on mechanical properties of Al‐containing Ti–Pd alloys." Journal of the American Ceramic Society 97.12 (2014): 3952-3957.4. Geng, Y., et al. "Investigation on corrosion behavior evolution of Ti-Pd alloys immersed in NaCl solution." Corrosion Science 56 (2012): 34-42.5. Guo, S., et al. "Effect of Ag content on the electrical conductivity of titanium-palladium alloys." Journal of Materials Science: Materials in Electronics 31.17 (2020): 14946-14952.。

Mechanical properties of steel fibre reinforced concrete

ORIGINAL ARTICLEMechanical properties of steel ﬁbre reinforced concrete exposed at high temperaturesMatteo Colombo ÆMarco di Prisco ÆRoberto FelicettiReceived:28September 2008/Accepted:1May 2009/Published online:15May 2009ÓRILEM 2009Abstract Steel ﬁbre reinforced concrete (SFRC)is an advanced cementitious composite where ﬁbres can act as a proﬁtable replacement for diffused reinforce-ment,like welded steel mesh,especially for thin cross sections.In this case ﬁre becomes a very important condition in the design.Previous experimental research has shown the beneﬁts in ﬁre resistance of steel ﬁbres,when structural elements are bent.A careful mechanical characterization of a SFRC used for prefabrication after thermal cycles at high tem-perature is here presented.Three different tests are considered:four point bending,uniaxial compression and ﬁxed-end uniaxial tension.In the paper the decay of peak and post-cracking strengths versus tempera-ture increase for uniaxial compression,uniaxial tension and bending are discussed.Keywords Steel ﬁbre reinforced concrete (SFRC)ÁHigh temperature ÁBending ÁUniaxial tension ÁUniaxial compression ÁResidual strength ÁThermal damage1Research signiﬁcanceThe research discussed in this paper was instrumental in suggesting and validating the ﬁre design approach proposed in the Italian National Recommendation CNR DT204/06recently issued about the design of ﬁbre reinforced concrete structures.In the whole research programme particular attention has been paid to the bending behavior of the material and to the identiﬁcation procedure of the uniaxial tensile constitutive law for FRC even at high temperatures.A suitable experimental investigation is here pre-sented aimed to identify the material properties of SFRC after a thermal damage.2IntroductionCementitious composites are typically regarded as quasi-brittle materials,with low tensile strength and strain capacity and limited fracture energy.However with the use of ﬁbre reinforcement,the brittleness shown by plain concrete structures can be overcome and structures with improved load bearing capacity,ductility and durability can be produced [1].In the last 30years the effect on toughness,fracture behaviour,impact performance of ﬁbres randomly distributed in the matrix has been investigated [2–4],including the improved performance allowed by ﬁbre hybridization.M.Colombo (&)ÁM.di Prisco ÁR.Felicetti Department of Structural Engineering,Politecnico di Milano,Milan,Italy e-mail:matteo.colombo@polimi.it URL:www.stru.polimi.itMaterials and Structures (2010)43:475–491DOI 10.1617/s11527-009-9504-0New High-Performance cementitious composites exhibiting an enhanced elastic limit as well as a strain-hardening response after cracking in bending or even in uniaxial tension have been also developed [5–8].The applications of these materials ask the researchers to better investigate the improvement of mechanical characteristics such as fatigue,impact,ﬁre behaviour,durability and shrinkage provided by ﬁbre addition[9].Fire condition is a very important issue in precast concrete structures and design and it is now regulated in Europe by European Standard EN1992-1-2 (Eurocode2).Researchers are very interested in this matter[10–13]and some open projects are now investigatingﬁre effects on different kind of struc-tures and in particular on tunnel linings:two large-scale experimental investigations on this matter have being carried out in Austria and in Germany[14].The use of steelﬁbre coupled with polypropylene ﬁbre[15]can provide some beneﬁts to structures. First of all,the prevention of spalling phenomena, given by polypropyleneﬁbre,avoids the steel rein-forcement to be directly exposed toﬁre thus reaching very high temperatures with a consequent mechanical decay.Moreover steelﬁbre give the material a certain residual bending resistance even when exposed to high temperature,improving the bearing capacity of the structure itself.A recent experimental investigation has shown the beneﬁts given by steelﬁbres both to mechanical properties of the material at high temperature[10,11, 13,16]and toﬁre resistance of bent element[16].In the same research some tests were carried out in order to demonstrate that hot and residual mechanical properties of the material do not differ signiﬁcantly, at least in the range200–600°C[17].This result is the outcome of the material failure mechanism,which is governed byﬁbre pull-out rather thanﬁbre yielding.According to Felicetti[18],the investigated mate-rial exhibits a diffusivity slightly higher than an ordinary concrete and close to what measured for a plain high strength concrete(Fig.1).The experimental programme here described is part of the Ph.D.thesis of one author[19]whereaFig.1Equivalent thermal diffusivity of different concretes [18]Table1Mix design of the material investigated Constituent Type Contentkg/m3lb/yd3Cement I52.5R450788 Aggregates(siliceous)0/362010850/124407708/157101243 Plasticizer Acrylic 5.59.63 Total water195341 Filler Calcareous3052.5 Fibre Steel5087.5more detailed description of each experimental resultis available.3Experimental programmeThe experimental programme presented was plannedin order to perform a proper identiﬁcation of themechanical properties of a steelﬁbre reinforcedconcrete(SFRC)used to produce precast roofelements[20–22]and to investigate the stiffnessdegradation in bending,uniaxial tension and com-pression,when exposed to high temperatures.Thepossible inﬂuence onﬁbre alignment of the reducedthickness in such structure members has not beenherein considered and specimens of standard geo-metry have been adopted.The material cylindrical compressive strength is75MPa(10.7ksi)and theﬁbre content is equal to50kg/m3(87.5lb/yd3);steelﬁbres are low-carbon, Fig.3Experimental programmeFig.4Four point bendingtests:experimental set-uphooked end,30mm long and with an aspect ratio (ﬁbre length/ﬁbre diameter;l f /d f )equal to 45;all the aggregates were siliceous.The mix design is shown in Table 1.Twelve prismatic specimens,according to Italian Recommendation UNI 11039[23],were cast on 22July 2004at Magnetti Larco Buildings factory.The thermal treatment of the material was carried out in a fournace by performing some thermal cycles up to different maximum temperatures trying to reduce as much as possible the temperature gradients inside the specimens.Three different maximum temperatures (200,400and 600°C [392,752and 1112°F])were considered.A heating rate equal to 30°C/h (54°F/h)was used up to the maximum threshold;after this,a 2h stabilization phase was imposed in order to guarantee homogeneous temper-ature into the specimen.The cooling phase was performed with a rate of 12°C/h (21.6°F/h)down to 100°C (196°F),temperature from which the furnace was opened and the cooling continued at room condition because of the loss of linearity of the furnace due to thermal exchange with the external environment.In each cycle,three nominally identical specimens were introduced into the oven.In this way,all the specimens characterized by the same maxi-mum temperature had the same thermal history.The thermal cycles for the three maximum temperatures considered are summarized in Fig.2.The experimental programme consists in three different phases (Fig.3).The ﬁrst one refers to the mechanical characterization of the material by means of four point bending tests on notched specimen.Once tested,two cylinders 150mm (5.91in)long with a 75mm (2.95in)diameter were cored from each specimen:the ﬁrst one was tested in uniaxial com-pression,while the second one was notched and tested according to a ﬁxed end uniaxial tension testset-up.Fig.5Four point bending tests:nominal stress versus CTOD curvesIn order to investigate the stiffness degradation of the material,in the whole set of tests,some unload-ing–reloading cycles were performed.4Four point bending testsFour point bending tests were performed according to the Italian Recommendation UNI 11039on 150********mm (5.9195.91923.62in)notched specimens characterized by a notch depth equal to 45mm (notch/depth ratio equal to 0.3).The tests were carried out by considering as feedback parameter the CMOD value (Crack Mouth Opening Displacement,Clip 1;Fig.4).In order to measure the crack opening at the notch tip (CTOD),two LVDT transducers were used (LVDTs 1,2).Four different LVDTs were instrumental to measure the deﬂection under the load application points on both the specimen sides (LVDTs 3–6).In order to prevent that deﬂection measurements could be affected by crushing of the material at the supports,a proper frame was used (Fig.4).The experimental results of three nominally identical four point bending tests are shown in Fig.5in terms of the nominal stress (r N )versus CTOD curves;their average envelope curves(i.e.Table 2Bending tests experimental results TTestFibre numberY f If f eq0–0.6f eq0.6–39103mm9103in MPa psi MPa psi MPa psi 20°C 68°F20_11679.610.38 5.80828 5.59798 4.2560720_21649.350.37 5.73818 5.53791 4.1859720_3129 6.700.26 5.84834 4.88698 3.29470Average1538.550.345.798275.34762 3.91558Max(x i -x av )/x av21.67% 1.05%8.48%15.76%200°C 392°F200_1122 5.670.22 5.79827 4.15593 3.10443200_222411.500.45 5.57796 4.58655 3.52503200_31447.770.31 5.47781 4.16595 3.20457Average1638.310.33 5.61801 4.30614 3.27467Max(x i -x av )/x av38.33% 3.21% 6.58%7.46%400°C 752°F400_11257.120.28 2.91416 2.98426 1.50214400_2116 5.250.21 2.31330 2.66380 1.44205400_3110 6.300.25 2.78397 3.07439 2.27325Average117 6.220.24 2.67381 2.90414 1.74248Max(x i -x av )/x av15.64%13.31%8.30%30.97%600°C 1112°F600_1114 6.060.23 3.01429 2.69384 1.52218600_291 4.880.19 2.80399 2.67381 2.04292600_3125 6.600.26 2.63376 2.60371 1.00142Average1105.850.23 2.81401 2.653781.52217Max(x i -x av )/x av16.53%6.89%2.00%34.52%neglecting the unloading–reloading cycles)are shown in Fig.6.The mechanical strengths at increasing tempera-ture are listed in Table2and plotted in Fig.7.The strengths considered represent respectively:f If:ﬁrst cracking strength that can be related to thematrix tensile strength;it is the nominal stresscorresponding to a CTOD equal to25l m(9.83Á10-4in);f eq0–0.6:average nominal strength in the CTODrange between0.025mm(9.83Á10-4in)and0.625mm(0.025in)representing the Serviceabi-lity Limit State(SLS)residual strength;f eq0.6–3:average nominal strength in the CTODrange between0.625mm(0.025in)and3.025mm(0.119in)representing the Ultimate Limit State(ULS),when material behaviour is governed onlybyﬁbre pull-out mechanism.Looking at the experimental results,a big decay ofmaterial properties between200°C(392°F)and400°C(752°F)is observed.For higher temperaturesthe material properties seem to remain quite constant;for temperatures lower than200°C(392°F)theﬁrst Fig.8Four point bendingtests average results:CMOD/CTOD versusCMOD curve,deﬂection(d av)/CTOD versus CMOD,load versus deﬂection(d av)and energy versusdeﬂection(d av)cracking nominal strengths do not seem to be affected by thermal treatment.It is important to underline that the critical section always corresponds to the notched one.The kinematical behaviour of the specimens is described in Fig.8a,b by means of CMOD/CTOD versus CTOD curve and of the average deﬂection (d av )/CTOD versus CMOD.These curves show how,after a short initial phase,the rigid body kinematical assumption is quite reliable even at high tempera-tures.The average load versus average deﬂection (d av )and the cumulative energy are represented respectively in Fig.8c,d.The whole Fig.8refers to average behaviour of three nominally identical specimens.In order to understand if the scattering in the residual strengths is governed by ﬁbre distribution in the critical cross section,ﬁbres were counted and their distance from the extrados was detected.This measure was instrumental to deﬁne the normalized bending resistant cumulative lever arm (Y =(R i a Áy i )/a;a =single ﬁbre cross section area;y i =distance of the i-th ﬁbre from the upper side of the cross section)with respect to the extrados of the cross section (Table 2).The parameter introduced is physically meaningful when the bending stiffnessofcompression tests:(a )experimental set-up,(b )a specimen view during the test,(c ,d )crack pattern for test 20_2and 600_2respectivelythe single ﬁbre crossing the crack is negligible in relation to the stiffness of the two concrete blocks which open and slide at the crack interface.If the real ﬁbre orientation is neglected,the distance of the ﬁbre barycentre from the upper side of the cross section can be correlated to the ratio between the normalized resistant modulus and num-ber of ﬁbres for each specimen.The number of detected ﬁbres reveals a quite high dispersion (st.dev.=27.12%)even if the average number is relatively close to the expected value according to Soroushian and Cha-Don [24](experi-mental average =130;expected value =139).The normalized resistant cumulative lever arm measured was not uniform for the different specimens tested at various temperatures:the maximum values were obtained for T =20and 200°C (respectively 8550mm and 8310mm against an expected value of 7298mm).According to the values indicated in Table 2the average barycentre position of ﬁbre reinforcement for the specimens tested at different temperatures (20,200,400,600°C),evaluated as Y/ﬁbre number,was respectively 55.76,50.88,53.16and 53.18mm,thus showing an average maximumvariation with respect to the expected value (52.5mm)close to 5%.5Uniaxial compression testsUniaxial compression tests were performed on cylinders cored from the beam after the bending test.Specimens were instrumented by means of seven LVDT transducers:three disposed at 120°around the specimen in order to measure the displacement between the press platens,three more LVDTs,always arranged at 120°,were applied to the central zone of the specimen with a gauge length equal to 50mm (1.97in);ﬁnally a LVDT connected to a chain clamped on the specimen was used to measure its circumferential relative displacement in the central region.The geometry and the spec-imen set-up in uniaxial compression are shown in Fig.9a,b.In order to reduce friction between the press platens and the specimen ends,stearic acid was introduced [25].All the tests weredisplacementcompression testsexperimental results:stress versus normalized total displacement curvescontrolled by using as feedback parameter the vertical displacement of the specimen between the press platens measured by one of the LVDTs.The displacement rate imposed was equal to 0.1mm/min (0.236in/h)either in the loading and unloading phases.The experimental results are shown in Fig.10in the form of nominal stress (r N =P/A;A =initial cross section area)versus normalized total vertical displacement (d /l;l =specimen length =150mm)curves.In only one test,carried out at room condition,a sudden failure occurred before reaching the peak load,caused by some instabilities in the test control.Even though the adoption of ring chain as feedback parameter could be helpful in stabilizing the loading procedure,a previous calibration of the vertical displacement gain,carried out on similar specimens,suggested to consider these kinematical measures as reliable.The variation of peak nominal strength is summarized in Table 3and Fig.11;in compression tests,unlike what happened in bending,the degrada-tion of the material starts since the lowest tempera-ture investigated;in the range between 200°C (392°F)and 400°C (752°F)the peak nominal strength seems to be less inﬂuenced by temperature increase.In the same ﬁgure,the peak strength decay experimentally detected is compared with the one proposed by Eurocode 2(EN1992-1-2)for plain concrete.The crack patterns at failure shown (Fig.9c,d)for the extreme thermal conditions investigated (T =20and 600°C)highlight how in both cases the collapse occurred after an inclined crack band propagation.The average of the envelope mechanical behaviour for different maximum temperatures is shown in Fig.12.In this ﬁgure the nominal stress is respec-tively plotted with respect to the normalized total vertical displacement (d /l),on the left side,and to the normalized circumferential displacement on the right side.In the latter case the circumferential displace-ment (d r ),read from the transducer placed on the chain clamped on the specimen,is divided by the perimeter of the cylinder cross section (p/).Taking into account both the longitudinal (e long =d /l)and the transversal normalised displace-ment (e transv =d r /p/),the volumetric strain (e v =e long ?2e transv )was evaluated and the average stress/peak stress (r /r p )versus e v is shown in Fig.13a.Obviously such parameter (e v )corresponds to a real strain up to the onset of the inclined crack band localisation:after this occurrence the measureTable 3Uniaxial compression tests experimental results TTestPeak strainPeak stress MPapsi 20°C 68°F20_10.003575.3410.7620_20.003679.2511.3220_30.003570.7010.10Average 0.003574.9810.71Max(x i -x av )/x av2.70% 5.71%200°C 392°F200_10.002560.268.61200_20.003264.819.26200_30.003460.898.70Average 0.003061.998.86Max(x i -x av )/x av17.30% 4.55%400°C 752°F400_10.004059.528.50400_20.003756.468.07400_30.003560.028.57Average0.003858.678.38Max(x i -x av )/x av 7.11% 3.77%600°C 1112°F600_10.003844.98 6.43600_20.003657.578.22600_30.005138.20 5.46Average 0.004246.92 6.70Max(x i -x av )/x av22.56%22.70%corresponds to the relative sliding between the two specimen blocks.Comparing the normalized circumferential dis-placement with the total vertical one the evolution of Poisson’s ratio at increasing temperature can be detected by taking into account the ratio between these two quantities in the initial elastic branch of each curve in the range between 5%and 30%of the peak load.The evolution of the Poisson ratio is represented in Fig.13b;the main contribution of temperature occurs in the range between 200°C (392°F)and 400°C (752°F)[26].The increase of volumetric strain e v after the peak can be correlated to a less localized failure due to thermal damage introduced.6Fixed end uniaxial tension testsUniaxial tension tests were carried out on notched cylinders (Fig.14c,d)glued to the press platens by means of an epoxy resin.The specimen was instru-mented with six LVDTs:three were placed astride the notch (gauge length =50mm [1.97in])to measure crack opening displacement (COD)and three were used to measure the relative displacement between the two end platens of the press.One of these was used as feedback parameter in test control.The displacement rate imposed during the tests was equal to 0.04l m/s (5.66Á10-3in/h)either in load-ing and unloading phases up to a COD equal to 0.6mm (0.0236in)and then,during ﬁbrepull-outFig.12Uniaxial compression tests experimental results:averagebehavioursFig.13Uniaxial compression tests experimental results:(a )volumetric strain versus stress over peak stress ratio,(b )Poisson’s ratio at different temperaturesmechanism,it was increased up to 0.4l m/s (5.66Á10-2in/h).In order to keep the platens parallel during the test,an active control was performed (Fig.14a,b)[27].Four steel bars with a 14mm (0.55in)diameter were used to connect the ﬁxed base of the press with the upper plate connected to the specimen and to an articulated joint.The bars were ﬁxed to a steel frame made of HEA100beams connected to the basement of the press.These bars have an adjustable length by means of a turnbuckle and each bar was instrumented with two strain-gauges to measure its elongation.Acting on the turnbuckles during the tests,it was ensured that all the crack opening measurements were very close,so far as to consider the plates as ﬁxed.For all temperatures,three nominally identical tests were carried out.In only one test (T =200°C [392°F])some problem occurred in the press control and the mechanical response was lost.The scattering observed in the response of the pristine specimen is really negligible (\2%)consid-ering the type of test (uniaxial tension)and the heterogeneity of the material (SFRC).The experimental results are shown in Fig.15by means of nominal stress (r N )versus average crack opening displacement (w)curves;the crack opening was computed as average relative displacement astride the notch.The envelope average curves r N versus crack opening w are shown in Fig.16.It is surprisingtotests set-up:(a )ﬁxed end active control,(b )general,(c )notched specimen and (d )specimen viewsverify how a previous experimental investigation carried out on prismatic specimen made of the same material subjected to the same thermal treatment and using a similar set-up [16]exhibited very closemechanical response both in terms of peak and residual strength.In order to better investigate the uniaxial tensile behaviour of SFRC when exposed to high temperatures the evolution of three different nominal strength is considered:r N peak :nominal stress at peak that represents the matrix behaviour;r N,0.15:average nominal stress in the crack opening displacement (w)range 0.15mm (0.0177in)±20%;r N,0.9:average nominal stress in the crack opening displacement (w)range 0.9mm (0.0354in)±20%related to pull-out mechanism.The evolution of these parameters is summarized in Table 4and shown in Fig.17.As already seen in the bending behaviour the highest material degrada-tion occurs in the temperature range between 200°C (392°F)and 400°C (752°F);out of this range the nominal strengths considered are quite constant.The pull-out mechanism seems to increase the strength between 400°C (752°F)and 600°C (1112°F);this behaviour is similar to the one observed in aprevioustests experimental results:stress versus average crack opening displacement (w)curvesexperimental investigation[16]on a nominally identical material.The experimental results of four uniaxial tension tests are shown in Fig.18,one for each temperature tested:the curves nominal stress(r N)versus crack opening displacement(COD)w cumulated in each gauge length highlight a very good control of the three LVDTs.The active control carried out to guarantee theﬁxed end platen condition involved the rising of a bending moment corresponding to the turn-buckle action applied to the specimen to limit the difference between the three w measurements at a value smaller than5%of the average actual displacement.The bending moments applied to the specimens were computed by means of the four strain measure-ments of the stiffening bars:the two moment compo-nents,respectively along x(M x)and along y(M y),are represented in Fig.19together with the eccentricities (M/N)in both directions.It is quite interesting to observe how in the last branch of the curve, corresponding to the behaviour after the breakpoint in the r N versus w curve,the bending moment is quite constant.Such occurrence can be explained by considering that in this zone the crack was already propagated to the whole cross section and the mechanical behaviour is mainly governed byﬁbre pull-out mechanism in which the elastic strain becomes negligible with respect to plastic component. This occurrence leads to a very small elastic rotation increment and consequently a quite constant moment.Table4Uniaxial tensile tests experimental results –,the test did not reach w=0.9mm(0.035in)T Test Peak stress r N,0.15r N,0.9MPa psi MPa psi MPa psi20°C68°F20_1 5.25750 2.00278 1.3120_2 5.21 1.32 1.99284 1.3218920_3 5.27 1.32 1.95279 1.32188Average 5.24 1.32 1.96281 1.32188Max(x i-x av)/x av0.57% 1.34%0.16%200°C392°F200_1 5.06 1.30 1.68240 1.30186200_2 4.92 1.30 2.46352 1.30186Average 4.99 1.30 2.07296 1.30186Max(x i-x av)/x av 1.40%18.94%0.11%400°C752°F400_1 2.61- 1.06151--400_2 2.060.650.941340.6593400_3 2.470.99 1.402000.99141Average 2.380.82 1.131620.82117Max(x i-x av)/x av13.45%23.62%20.73% 600°C1112°F600_1 1.730.80 1.452070.80114600_2 2.460.71 1.652350.71102600_3 2.37 1.09 2.04292 1.09156Average 2.190.87 1.712450.87124Max(x i-x av)/x av21.00%19.29%25.29%In addition to this,a huge difference between the rotational stiffness of the steel frame used to keep the platens ﬁxed and the specimen stiffness,when high crack opening displacements are reached,induces a lack of sensitivity in applying the moment to the specimen.Also the choice of keeping the difference between the three COD measurements lower than 5%the actual average COD,allows the specimen a higher absolute rotation in the last phase of the test;in this case some of the external ﬁbres are more pulled out and therefore the barycentre position moves towards the external surface.In fact,the tangential stiffness of the softening branch is much smaller than the unloading one.This can be clearly seen in Fig.19,where both the eccentricities grow even when the moment is ﬁxed,due to the decrease of the axial tensile force.In the same ﬁgures the barycentre coordinate are indicated:they are computed by considering ﬁbre distribution over the cross section (Fig.20)and ignoring ﬁbre cross section orientations.Finally,the average trend of the absolute value of both the eccentricities is computed for different tempera-tures (Fig.21).Looking at the difference between thecurves at different temperatures it can be argued that inside the representative volume here considered (circular Sect.75mm [2.95in]diameter)the ethero-genity observable at room temperature grows even when a uniform thermal distribution is imposed because of the lack of compliance among the different constituent due to un-homogeneous thermal dilation.This effect can also affect pull-out mechanism.This observation is also conﬁrmed by the higher scattering highlighted in the tensile response when thermal damage is introduced.7ConclusionsFrom the experimental results obtained in this investigation some important concluding remarks can be highlighted.–Fibre pull-out mechanism,which controls the post-cracking behaviour,is less affected by higher temperature than the matrix of plain concrete:up to 400°C (752°F).Thepost-crackingFig.18Uniaxial tensile tests experimental results:nominal stress versus crack opening curvesstrength decay in bending is less marked.Looking at the experimental results in the range between 400°C (752°F)and 600°C (1112°F)theparameters related to pull-out mechanism remain constant or even grow.As a matter of fact,in bending tests,nominal equivalent strength f eq 0.6–3remains quite constant once 400°C (752°F)is reached,while the post-cracking strength (r N,0.9)in uniaxial tension even grows from 400(752°F)to 600°C (1112°F).–With reference to compressive strength (scantly affected by pull-out mechanism),a quite linear decay of the mechanical properties of the material with temperature has been detected,conﬁrming that such ﬁbre addition does not signiﬁcantly inﬂuence ﬁre resistance in uniaxial compression.The experimental device used allowed us to investigate Poisson’s coefﬁcient versus maximum temperature:the coefﬁcient remains constant up to 200°C and,as thermal decay,signiﬁcantly increases in the range 200–400°C reaching a peak of 0.325at 400°C (752°F);besides,it returns to a value of 0.28.–Concerning the uniaxial tensile tests,the results here discussed prove that,in the cylin-drical specimens,ﬁxed end platen guaranteeanFig.19Uniaxial tensile tests experimental results:bending moment and eccentricities in x and y direction applied by the stiffening system;coordinates of the ﬁbre barycentre (1mm =0.039in;1kNm =8.85in*kips)Fig.20Fibre distribution over the cross section for uniaxial tensile test 20_2and coordinate system deﬁnition。

ENAC-46000alloy

A R C H I V E So fF O U N D R Y E NG I N E E R I N G Published quarterly as the organ of the Foundry Commission of the Polish Academy of Sciences ISSN (1897-3310) Volume 10Issue 4/2010169 – 17232/4Effect of modification and heat treatment operations on impact strength of theEN AC-46000 alloyJ. PezdaFaculty of Chipless Forming Technology, University of Bielsko-Biała,Willowa 2, 43-309 Bielsko - Biała, PolandCorrespondingauthor.E-mailaddress:******************.plReceived 06.07.2010; accepted in revised form 15.07.2010AbstractMore and more stringent requirements concerning mechanical and technological properties, which are imposed on materials used to castings of heavy duty machinery components extort implementation of modern selection methods of alloying additives (synthesis of alloys), modifying agents and heat treatment. Obtainment of optimal results, i.e. improvement of mechanical properties of processed alloy as well as its economic aspect are connected with selection of a suitable temperatures and durations of solution heat treatment and ageing operations. In the paper is present an effect of modification and heat treatment processes on KCV impact strength of the EN AC-46000 alloy. Investigated alloy underwent typical treatments of refining and modification, and next heat treatment. Temperatures’ r ange for heat treatment operations was evaluated with used of the ATD method. Obtained results concern registered curves of melting and solidification with use of the ATD method and the impact strength. On base of performed tests one has determined a range of heat treatment parameters which create conditions to suitable impact strength of the EN AC-46000 alloy.Keywords: Modification, Heat treatment, ATD, Impact strength1. IntroductionNowadays, aluminum and its alloys (except iron) find the broadest implementation in any type of design structures. It is connected both with its mechanical properties and with good founding properties, good machineability and thermal conductance [1-3].Mechanical properties of silumins are determined by their chemical composition and structure of an alloy which undergoes a changes after refining, modification and heat treatment, i.e. treatments aimed at growth of mechanical properties of the alloy. In such area are performed a comprehensive investigations, aimed at permanent growth of competitiveness of the Al-Si alloys, comparing with another structural materials [1,2,4-18].Moreover, it is not possible to neglect an effects of technological conditions of alloy preparation, i.e. correct selection and batching of modifying agent, temperature of the metal, time elapsing from modification to solidification of the alloy, because even optimally selected modifying agent is not able to fulfill its task in case of faulty selected technological conditions.Equally important issue is taking the best from theory of crystallization and methods based on analysis of tem peratures’ change course (ATD, DTA) as well as temperature and voltage change (ATND) [1,2,19]. These methods enable registration of crystallization processes and a phenomena occurring in course of their duration. Analysis of course of the recorded curves enablesassessment both of extend of alloy’s modification and temperatures’ range of solution heat treatment and ageing treatment [15].Among methods of investigation of mechanical properties of alloys, the impact test constitutes a sensitive method to assess effects being result of performed processes of modification of hyper- and hypoeutectoid silumins [3].2. Methodology of the researchThe EN AC-46000 (EN AC-AlSi9Cu3(Fe)) alloy is characterized by very good casting and technological properties. Due to very good mechanical properties, this alloy is used for heavy duty components of machinery, like cylinder heads and pistons of engines.The first stage of the investigations consisted in testing of crystallization course for the alloy. Process of solidification and melting of the alloy was recorded with use fully automated Crystaldimat analyzer.Next, one performed treatment of refining with use of Rafal 1 preparation in quantity of 0,4% mass of metallic charge. After completion of the refining there were removed oxides and slag from metal-level and performed operation of modification with strontium, making use of AlSr10 master alloy in quantity of 0,5% mass of metallic charge (0,05% Sr).The heat treatment was performed for the refined and modified alloy. This treatment consisted in putting the test pieces poured from the investigated alloy to solutioning and ageing. Temperatures of these treatments were selected on base of points’ values taken from curves of the ATD method.In the Fig. 1 are shown recorded curves of heating (melting) and crystallization of refined and modified alloy, recorded with use of the ATD method, with marked temperatures of solutioning and ageing treatments.Fig. 1. Curves of the ATD method for refined and modifiedEN AC-AlSi9Cu3(Fe) alloyIn the Table 1 are shown parameters of the heat treatment for three stage plan of investigations with four variables, on base of this plan there were determined values of temperatures and durations of solutioning and ageing treatments aimed at obtainment of the best KCV impact strength of the alloy. For the assumed plan of the investigations, number of configurations amounts to 27.Table 1.Heat treatment parameters of the alloysolutioningtemperaturet p [o C]solutioningdurationp[h]ageingtemperaturet s [o C]ageingdurations[h]t p1 - 175 2 t s1 - 485 0,5t p2 - 240 5 t s1 - 510 1,5t p3 - 320 8 t s1 - 545 3The next stage of the investigations consisted in the impact tests of the investigated alloy. The impact test was performed with use of the Charpy pendulum machine.3. Description of obtained resultsImpact strength of the raw alloy amounted to from 2,2 up to 2,4 J/cm2. After refining, one obtained the impact strength in range of 2,6 to 2,8 J/cm2. Modification treatment resulted in growth of the impact strength, which amounted to from 2,9 up to 3,1 J/cm2. In the Fig. 3 is presented a change of the impact strength after performed heat treatment for refined and modified alloy in all points of the plan taken to investigations.Fig. 2. Change of the KCV impact strength of the investigated alloy for individual configurations of the testing planThe KCV impact strength of the EN AC-46000 has reached its the highest values for the points 12, 15 and 18 (Fig. 2), where temperature of solutioning, temperature of ageing and duration of ageing were the same (t p= 510°C, t s =320°C and p=8 h), whereasJ/cm2duration of the solutioning was different in each of these points, and respectively amounted to:- 0,5 h for the point 12,- 1,5 h for the point 15,- 3 h for the point 18.Impact strength in these points amounted to from 7,2 up to 10,9 J/cm2. The lowest impact strength of the investigated alloy was obtained for the points 20, 25, 26 (Fig. 2). Impact strength for these points was in limits of 1,5 - 2 J/cm2.In effect of the performed heat treatment one obtained a growth of the impact strength of the alloy, reaching up to 350% with respect to not-modified alloy.In the Figs. 3 and 4 is shown an effect of temperature and duration change of solutioning and ageing on the KCV impact strength of the investigated alloy.Fig. 3. Effect of temperature and duration of solutioning on impact strength of the EN AC-46000 alloyFig. 4. Effect of temperature and duration of ageing on impactstrength of the EN AC-46000 alloyOptimal temperature of solutioning for the investigated alloy, in aspect of change of its impact strenght, amounted to about 510°C (Fig. 3).On change of impact strength in case of the investigated alloy has an effect duration of its ageing (Fig.4), growth of the duration causes distinct change of impact strength of the EN AC-46000 alloy.4. ConclusionsThe ATD method has enabled assessment of temperatures’ ranges of solutioning and ageing treatments of the alloy used in assumed plan of the investigations.Proper selection of temperatures and durations of solutioning and ageing treatments enables obtainment of significant growth of impact strength of the EN AC-46000 alloy.Selection of temperatures and durations of solutioning and ageing treatments on base of performed initial tests was completed, making evaluation of their ranges, which enable obtainment of the highest impact strength of the alloy:a) temperature of solutioning - 500 510 o C,b) duration of solutioning - 0,5 to 3 h,c) temperature of ageing - 320 o Cd) duration of ageing - 8 h.References[1]P. Wasilewski, Silumins –Modification and its impact onstructure and properties, PAN Solidification of metals and alloys, Zeszyt 21, Monografia, Katowice 1993 r. (in Polish).[2]S. Pietrowski, Silumins, Wydawnictwo PolitechnikiŁódzkiej, Łódź, 2001 (in Polish).[3]Z. Poniewierski, Crystallization, structure and properties ofsilumins, WNT Warszawa 1989 (in Polish).[4]S. Pietrowski, T. Szymczak, Silumins alloy crystallization,Archives of Foundry Engineering, vol. 9 Iss. 3 (2009) 143-158.[5] A. Białobrzeski, P. Dudek, A. Fajkiel, W. Leśniewski,Preliminary investigations into the technology of continuous sodium modification of Al.-Si alloys, Archives of foundry, vol. 6 No. 18 (1/2) (2006) 97-103 (in Polish).[6]S. Pietrowski, T. Szymczak, B. Siemieńska-Jankowska, A.Jankowski, Selected characteristic of silumins with additives of Ni, Cu, Cr, Mo, W and V, Archives of Foundry Engineering, vol. 10, Iss. 2 (2010) 107-126.[7]L.A. Dobrzański, Ł. Reimann, G. Krawczyk, Influence of theageing on mechanical properties of the aluminium alloy AlSi9Mg, Archives of Materials Science and Engineering, vol. 31 Iss. 1 (2008) 37-40.[8]K. Nogita, S.D.. McDonald, A.K. Dahle, Eutecticmodification of Al-Si alloys with rare earth metals, Materials Transactions Publication, vol. 45, Iss. 2 (2004) 323-326. [9] C. H. Cáceres, Strength-ductility behaviour of Al-Si-Cu-Mgcasting alloy in T6 temper, Cast Metals Res., vol. 15 (2003) 531-543.[10]H.. Zhang, H. Duan, G. Shao, L. XU, Microstructure andmechanical properties of hypereutectic Al-Si alloy modified with Cu-P, Rare Metals vol. 27, Iss.1 (2008) 56-63.[11]A.Knuutinen A., K. Nogita ; S.D. McDonald; A.K. Dahle,Modification of Al-Si alloys with Ba, Ca, Y and Yb, Journal of Light Metals, vol. 1 No. 4 (2001) 229-240.[12]W. Orłowicz, M. Mróz, M. Tupaj, J. Betlej, F. Ploszaj,Influence of refining AlSi alloy on the porosity of pressure moulds, Archives of Foundry Engineering, vol. 9 Iss. 2 (2009) 35-40.[13]W. Orłowicz, M. Tupaj, M. Mróz, Mechanical properties ofAlSi7Mg alloy modified with sodium, Archives of Foundry Engineering, vol. 9 Iss. 2 (2009) 35-40 (in Polish).[14]J. Pezda, Effect of modifying process on mechanicalproperties of EN AC-43300 silumin cast into sand moulds, Archives of Foundry Engineering, vol. 8 Iss. 1 (2008) 241-244. [15]J. Pezda, Heat treatment of the EN AC-AlSi9Cu3(Fe) alloy,Archives of Foundry Engineering, vol. 10 Iss. 2 (2010) 99-102.[16]J. Pezda, Effect of modification with strontium onmachinability of AK9 silumin, Archives of Foundry Engineering, vol. 8 Special Iss. 1 (2008) 173-176.[17]R. Gorockiewicz, Effect of heat treatment on microstructureof silumins, Archives of foundry, vol. 3 No 9 2003 (in Polish).[18]Lu. Shu-Zu, A. Hellawel, Modyfication of Al-Si alloys:microstructure, thermal analysis and mechanics, IOM vol. 47 No 2, 1995.[19]P. Wasilewski, Comparison of testing methods ofsolidification and crystallization of alloys, Archives of Foundry, vol. 3 No. 10 (2003) (in Polish).。

Investigating the Properties of Materials

Investigating the Properties ofMaterialsInvestigating the properties of materials is an essential aspect of scientific research and development. Understanding how different materials behave under various conditions can lead to the creation of new and improved products, as well as advancements in technology and engineering. This process involves testing and analyzing the physical, chemical, and mechanical properties of materials to determine their suitability for specific applications. One of the key properties of materials that scientists and researchers investigate is their strength and durability. This involves testing the material's ability to withstand external forces, such as tension, compression, or bending, without breaking or deforming.By understanding the strength and durability of materials, engineers can design structures and products that are safe and long-lasting. For example, in the construction industry, the strength of materials such as concrete, steel, and wood is crucial for ensuring the stability and integrity of buildings and infrastructure. Another important property of materials is their thermal conductivity, which refers to their ability to conduct heat. This property is particularly significant in industries such as electronics and manufacturing, where the efficient transfer of heat is essential for maintaining the performance and reliability of equipment and processes. By investigating the thermal conductivity of materials, scientists can develop new materials with improved heat transfer capabilities, leading to advancements in thermal management and energy efficiency. In addition to strength and thermal conductivity, the electrical conductivity of materials is also a critical property that researchers investigate. Electrical conductivity refers to the ability of a material to conduct an electric current, and it is a fundamental property in the design and manufacturing of electronic devices and components. By studying the electrical conductivity of materials, scientists can develop new conductive materials that are essential for the advancement of technologies such as semiconductors, batteries, and electrical wiring. Furthermore, the chemical properties of materials play a significant role in their suitability for specific applications. For example, in the pharmaceuticalindustry, researchers investigate the chemical stability and reactivity of materials to ensure the safety and efficacy of drugs and medical devices. Understanding the chemical properties of materials is also crucial in the development of new materials for environmental remediation, such as adsorbents and catalysts for pollution control and waste treatment. Moreover, the optical properties of materials, such as their ability to transmit, reflect, or absorb light, are essential for a wide range of applications, including optics, photonics, and display technologies. Investigating the optical properties of materials allows scientists to develop new materials with improved optical performance, leading to advancements in imaging, communication, and lighting systems. In conclusion, investigating the properties of materials is a multifaceted and essential aspectof scientific research and development. By understanding and manipulating the physical, chemical, and mechanical properties of materials, scientists and researchers can drive innovation and progress in various industries, leading tothe creation of new and improved products, as well as advancements in technology and engineering. This process involves testing and analyzing the strength, thermal and electrical conductivity, chemical stability, and optical performance of materials to determine their suitability for specific applications. Ultimately,the investigation of material properties is fundamental to the advancement of science and technology, and it continues to play a crucial role in shaping the world around us.。

TSZ410铁素体不锈钢的高温力学性能试验

modulus，nominal yield strength，tensile strength，and elongation were obtained. The Rasmussen model and Gardner model were compared and analyzed. Based on the Rasmussen model，the calculation formula for the high-temperature stainless steel material hardening index was proposed and the high temperature stress-strain constitutive relationship of TSZ410 stainless steel was established. Compared with Q235B， S30408 austenitic stainless steel and EN 1.4003 stainless steel，the law of the effect of temperature on its mechanical properties was revealed. The results indicate that the initial elastic modulus， the nominal yield strength， and the tensile strength of TSZ410 stainless steel decrease gradually with the increase of temperature，especially in the temperature segment of 400℃ to 700℃，and the rate of decline is most significant. When heating temperatures are equal to 700°C， the elastic modulus is reduced to 40% of the normal temperature elastic modulus， and the nominal yield strength and tensile strength are reduced to about 15% of the nominal yield strength and tensile strength at room temperature. At a high temperature，the strength loss of TSZ410 stainless steel is larger than that of Q235B，while the stiffness loss is obviously less than that of Q235B. At a temperature below 500 ℃，TSZ410 stainless steel strength loss is significantly less than S30408 austenitic stainless steel，but when the temperature is higher than 500 ℃，the opposite is true.

金属材料试样制备与力学性能试验结果的相关性_省略_取样部位及机加工与力学性能试验

技术讲座金属材料试样制备与力学性能试验结果的相关性第一讲　试样的取样部位及机加工与力学性能试验结果的相关性王承忠(宝钢特殊钢分公司质量保证部,上海200940)摘　要:介绍了金属材料试样制备与力学性能试验结果的相关性。

对国家标准中关于力学性能试验试样取样和机加工的要求、力学试验取样和制样过程中需要注意的问题、机加工质量的检验等问题进行了讨论。

结果表明金属材料试验试样的制备与力学性能试验的结果有着非常密切的相关性,由于这个原因,力学试验试样的取样和机加工必须严格按照国家标准的要求进行,机加工后必须检验加工质量,以保证力学试验结果的正确性。

关键词:试样机加工;取样;制样;力学性能;相关性;力学试验中图分类号:T G115.5 文献标识码:A 文章编号:100124012(2008)0120033204R EL A TIV IT Y B ETWEEN PR EPA RA TION O F SPECIM ENS AND R ESUL TSO F M EC HAN ICAL PRO PER T Y TESTIN G FOR M ETALL IC MA TERIAL S L EC TU R E No.1　R EL A TIV IT Y FOR LOCA TION O F SAM PL IN G&PROCESS MAC H IN IN G AND R ESUL TS O F M EC HAN ICAL PRO PER T Y TESTIN GWANG Cheng2zhong(Baoshan Iron&Steel Co.L td.,Special Steel Branch,Shanghai200940,China) Abstract:The relativity for preparation of specimens and results of mechanical testing for metallic materials was introduced in a systematic way.The requirement of Chinese standards to location of sampling and process machining of test pieces for mechanical testing,the needing attention problems of the process for sampling and preparation of test pieces for mechanical testing,the examine of quality for process machining etc.were also discussed.The results showed that the relativity for preparation of specimens and results of mechanical testing for metallic materials were very close relationship.For the reason the location of sampling and process machining of test pieces for mechanical testing must be in processing strictly according to the requirement of Chinese standards.After the process machining must inspect the quality of processing.The exactitude of the results for mechanical testing is guaranteed.K eyw ords:Process machining of specimens;Sampling;Preparation of specimens;Mechanical property;Relativity;Mechanical testing 金属材料是工程材料中的主体,其力学性能是工程应用中十分重要的性能。

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