机械外文翻译---切削加工新概念

机械外文翻译---切削加工新概念
机械外文翻译---切削加工新概念

The New Concept Of Cutting Processing

The nowadays cutting tool company cannot only be again the manufacture and the sales cutting tool, in order to succeed, they must be consistent with the globalization manufacture tendency maintenance, through enhances the efficiency, cooperates with the customer reduces the cost. Approaches the instantaneous global competition after this after NAFTA, the WTO time, the world company is making quickly to the same feeling, is lighter, a cheaper response. In other words, they make the product and the components contain can in high speed under revolve, as a result of the cost pressure, best, is lighter moreover must make cheaply. Obtains these goals a best way is through develops and applies the new material, but these is new and the improvement material usually all with difficulty processes. In in this kind of commercial power and the technical difficulty combination is especially prominent in the automobile and the aviation industry, and has become has the experience the cutting tool company to research and develop the department the most important driving influence.

For example, takes the modular cast iron to say that, it has become the engine part and other automobiles, the agriculture the material which see day by day with the equipment and in the machine tool industry components. This kind of alloy provides the low production cost and the good machine capability combination. They are cheaper than the steel products, but has a higher intensity and toughness compared to the cast iron. But at the same time the modular cast iron is extremely wear-resisting, has fast breaks by rubbing the cutting tool material the tendency. In this wear resistant very great degree bead luminous body content influence. Some known modular cast iron bead luminous body content higher, its resistance to wear better, moreover its machinability is worse. Moreover, the modular cast iron porosity causes off and on to cut, this even more reduces the life.

May estimate that, the high degree of hardness and the high wear-resisting cutting material quality must consider the modular cast iron the high resistance to wear. And the material quality contains extremely hard TiC in fact (carbonized titanium) or TiCN (carbon titanium nitrides) thick coating when cutting speed each minute 300 meters processes the modular cast iron to prove usually is effective. But along with cutting speed increase, scrap/The cutting tool junction plane temperature also is increasing. When has such situation, the TiC coating favors in has the chemical reaction with the iron and softens, more pressures function in anti- crescent moon hollow attrition coating. Under these conditions, hoped has one chemical stability better coating, like Al2O3 (although under low speed was inferior to TiC hard or is wear-resisting).

The chemical stability becomes an important performance performance dividing line compared

to the resistance to wear the factor, the speed and the temperature is decided in is processed the modular cast iron the crystal grain structure and the performance. But usually thick coating of TiCN and TiC or only ductile iron oxides in the soil coating is applied to, because the today majority of this kinds are processed the material the cutting speed in each minute 150 to 335 meters between. Is higher than each minute 300 meter applications regarding the speed, the people to this kind of material are satisfied.

In order to cause this scope performance to be most superior, the mountain high researched and developed and has promoted in view of modular cast iron processing material quality TX150. This kind of material quality has hard also the anti- distortion substrate, is very ideal regarding the processing modular cast iron. Its coating the oxide compound coating which hollowly wears by thick very wear-resisting carbon titanium nitrides and a thin anti- crescent moon, the top is thin layer TiN. This kind of coating which needs the center warm chemistry gas phase deposition using the state of the art production resistance to wear and the anti- crescent moon hollow attrition which the CVD coating complete degree of hardness moreover the tough smoothness increases (MTCVD) the craft. Substrate/The coating combination performance gives the very high anti- plastic deformation and the cutting edge micro collapses the ability, causes it to become under the normal speed to process the modular cast iron the ideal material quality.

The coating ceramics also display can effectively process the modular cast iron. In the past, the aluminum oxide ceramics application which not the coating tough good such as nitriding silicon and the silicon carbide textile fiber strengthened the work piece material chemistry paralysis limit. Today but could resist the scrap distortion process through the use to have the high thermal coating cutting tool life already remarkably to increase. But certain early this domains work piece processing use aluminum oxides spread the layer crystals to have to strengthen the ceramics, today most research concentrate in the TiN coating nitriding silicon. This kind of coating can remarkably open up the tough good ceramics the application scope.

When machining, the work piece has processed the surface is depends upon the cutting tool and the work piece makes the relative motion to obtain.According to the surface method of formation, the machining may divide into the knife point path law, the formed cutting tool law, the generating process three kinds.

The knife point path law is depends upon the knife point to be opposite in the work piece surface path, obtains the superficial geometry shape which the work piece requests, like the turning outer annulus, the shaping plane, the grinding outer annulus, with the profile turning forming surface and so on, the knife point path are decided the cutting tool and the work piece relative motion which provides in the engine bed;

The formed cutting tool law abbreviation forming, is with the formed cutting tool which

matches with the work piece final superficial outline, or the formed grinding wheel and so on processes the formed surface, like formed turning, formed milling and form grinding and so on, because forms the cutting tool the manufacture quite to be difficult, therefore only uses in processing the short formed surface generally;

The generating process name rolls cuts method, is when the processing the cutting tool and the work piece do unfold the movement relatively, the cutting tool and the work piece centrode make the pure trundle mutually, between both maintains the definite transmission ra tio relations, obtains the processing surface is the knife edge in this kind of movement envelope, in the gear processing rolls the tooth, the gear shaping, the shaving, the top horizontal jade piece tooth and rubs the tooth and so on to be the generating process processing.Some machining has at the same time the knife point path law and the formed cutting tool method characteristic, like thread turning.

The machining quality mainly is refers to the work piece the processing precision and the surface quality (including surface roughness, residual stress and superficial hardening).Along with the technical progress, the machining quality enhances unceasingly.The 18th century later periods, the machining precision counts by the millimeter; At the beginning of 20th century, machining precision Gao Yida 0.01 millimeter; To the 50's, the machining precision has reached a micron level; The 70's, the machining precision enhances to 0.1 micron.

The influence machining quality primary factor has aspects and so on engine bed, cutting tool, jig, work piece semifinished materials, technique and processing environment.Must improve the machining quality, must take the suitable measure to the above various aspects, like reduces the engine bed work error, selects the cutting tool correctly, improves the semifinished materials quality, the reasonable arrangement craft, the improvement environmental condition and so on.

Enhances the cutting specifications to enhance the material excision rate, is enhances the machining efficiency the essential way.The commonly used highly effective machining method has the high-speed cutting, the force cutting, the plasma arc heating cuts and vibrates the cutting and so on.

The grinding speed is called the high-speed grinding in 45 meters/second above https://www.360docs.net/doc/1e4874987.html,es the high-speed cutting (or grinding) both may enhance the efficiency, and may reduce the surface roughness.The high-speed cutting (or grinding) requests the engine bed to have the high speed, the high rigidity, the high efficiency and the vibration-proof good craft system; Requests the cutting tool to have the reasonable geometry parameter and the convenience tight way, but also must consider the safe reliable chip breaking method.

The force cutting refers to the roughing feed or cuts the deep machining greatly, uses in the turning and the grinding generally.The force turning main characteristic is the lathe tool besides the main cutting edge, but also some is parallel in the work piece has processed superficial the

vice-cutting edge simultaneously to participate in the cutting, therefore may enhance to feed quantity compared to the general turning several times of even several https://www.360docs.net/doc/1e4874987.html,pares with the high-speed cutting, the force cutting cutting temperature is low, the cutting tool life is long, the cutting efficiency is high; The shortcoming is processes the surface to be rough.When force cutting, the radial direction cutting force death of a parent is not suitable for to process the tall and slender work piece very much.

The vibration cutting is along the cutting tool direction of feed, the attachment low frequency or the high frequency vibration machining, may enhance the cutting efficiency.The low frequency vibration cutting has the very good chip breaking effect, but does not use the chip breaking equipment, makes the knife edge intensity to increase, time the cutting total power dissipation compared to has the chip breaking installment ordinary cutting to reduce about 40%.The high frequency vibration cutting also called the ultrasonic wave vibration cutting, is helpful in reduces between the cutting tool and the work piece friction, reduces the cutting temperature, reduces the cutting tool the coherence attrition, thus the enhancement cutting efficiency and the processing surface quality, the cutting tool life may enhance 40% approximately.

To lumber, plastic, rubber, glass, marble, granite and so on nonmetallic material machining, although is similar with the metal material cutting, but uses the cutting tool, the equipment and the cutting specifications and so on has the characteristic respectively.

The lumber product machining mainly carries in each kind of joiner's bench, its method mainly has: The saw cuts, digs cuts, the turning, the milling, drills truncates with the polishing and so on.

The plastic rigidity is worse than the metal, the easy bending strain, the thermoplastic thermal conductivity to be in particular bad, easy to elevate temperature the conditioning.When cutting plastic, suitably with the high-speed steel or the hard alloy tools, selects the small to feed quantity and the high cutting speed, and uses compressed air cooling.If the cutting tool is sharp, the angle is appropriate, may produce the belt-shaped scrap, easy to carry off the quantity of heat.

Glass (including semiconducting material and so on germanium, silicon) but degree of hardness high brittleness is big.To methods and so on glass machining commonly used cutting, drill hole, attrition and polishing.To thickness in three millimeters following glass plates, the simple cutting method is with the diamond or other hard materials, in glass surface manual scoring, the use scratch place stress concentration, then uses the hand to break off.

To the marble, the granite and the concrete and so on the hard material processing, mainly uses methods and so on cutting, turning, drill hole, shaping, attrition and polishing.When cutting the available circular saw blade adds the grinding compound and the water; The outer annulus and the end surface may use the negative rake the hard alloy lathe tool, by 10~30 meter/minute cutting speed turning; Drills a hole the available hard alloy drill bit; The big stone material plane available

hard alloy planing tool or rolls cuts planing tool shaping; The precise smooth surfa ce, available three mutually for the datum to the method which grinds, or the grinding and the polishing method obtains.

Cutting tool in hot strong alloy application

The aviation processing also changes rapidly. For example, nickel base heat-resisting alloy like several years ago the most people had not heard Rene88 now occupies to the aircraft engine manufacture uses the total metal quantity 10~25%. Has very good showing and the commercial reason regarding this. For example, these heat strong alloy will be able to increase the engine endurance moreover to permit the small engine work on the big airplane, that will enhance the combustion efficiency and reduces the operation cost. These tough good materials also present the expense on the cutting tool. Their thermal stability causes on the knife point the temperature to be higher, thus reduced the cutting tool life. Similarly, in these alloy carbide pellet remarkably increased the friction, thus reduces the cutting tool life.

As a result of changes in these conditions, can be very pleased to have processed many titanium alloys and nickel-based alloy materials C-2 hard metal alloys, in the application to today's cutting edge of blade to the crushing and cutting depth of the trench lines badly worn. But using the latest high-temperature processing of small particles hard metal alloys to be effective, cutlery life improved, but more importantly to enhance the reliability of applications in high-temperature alloys. Small particles hard metal than traditional hard metal materials higher compression strength and hardness, only a small increase in the resilience of the cost. And resulted in high temperature alloy processing than traditional hard metal resistance common failure mode more effective.

PVD (physical gas phase deposition) coating also by certificate effective processing heat-resisting alloy. TiN (titanium nitrides) the PVD coating was uses and still was most early most receives welcome. Recently, TiAlN (nitrogen calorization titanium) and TiCN (carbon titanium nitrides) the coating also could very good use. In the past the TiAlN coating application scope and TiN compared the limit to be more. But after the cutting speed enhances them is a very good choice, enhances the productivity in these applications to reach 40%. On the other hand, is decided under the low cutting speed in coating superficial operating mode TiAlN can cause to accumulate the filings lump afterwards, micro collapses with the trench attrition.

Recently, used in the heat-resisting alloy application material quality already developing, these coating but became by several combinations. The massive laboratories and the scene test has already proven this kind of combination and other any kind of sole coating compares in time the very wide scope application is very effective. Therefore aims at the heat-resisting alloy application the PVD compound coating possibly to become the focal point which the hard alloy new material quality research and development continues. With the MTCVD coating, the coating ceramics gather

in the same place, they hopefully become a more effective processing to research and develop newly are more difficult to process the work piece material the main impact strength.

Dry processing

Including the refrigerant question is technical and the commercial expansion industrial production tendency another domain which the cutting tool makes. North America and the European strict refrigerant management request and the biggest three automobile manufacturer forces them the core supplier to obtain the ISO14000 authentication (the ISO9000 environment management edition), this causes the refrigerant processing cost rise. To the car company and their core supplier said obviously one of responses which welcome is in the specific processing application avoids completely the refrigerant the use. This kind did the processing the new world to propose a series of challenges for the cutting tool supplier.

Recently, already appeared some to concern this topic to promulgate the speed, to enter for, the coating chemical composition and other parameters very substantial comprehensive nature very strong useful technical papers. Wants to concentrate the elaboration in here me "does the processing viewpoint" in the operation and commercial meaning automobile manufacturer new.

The metal working jobholders can the very good understanding related refrigerant use question, but majority cannot understand concerns except the technical challenge (for example row of filings) beside does the processing question in the cutting tool - work piece contact face between. Usually may observe to the refrigerant disperser scrap which flows out, but the pressure surpasses 3,000 pounds/An inch 2 high speed refrigerant also can help to break the filings, specially soft also the continual scrap can cause in the cutting tool - work piece contact face trouble.

Uses does the cutting craft the components result is the engine bed uses the wet type processing components to be hotter than. Whether before you do allow them to survey in the open-air natural cooling? If processes newly the hot components put frequently to the turnover box, elevates the environment temperature, whether components full cooling and just right enough permission precision examination? Also has the handling side severa l dozens on hundred components to be able to operate the worker to increase the extra burden.

With many cutting tools/The work piece technical question same place, these latent questions need to state whether dryly adds the ability line. Luckily, has very many ways to elaborate these questions. For example, the compressed air was proven row of filings becomes the question in very many applications the situation to have the successful echo.

Another plan is called MQL (minimum lubrication) a technology, it replaces the traditional refrigerant by the application the quite few oil mists constitution. This is a recognition compromise plan, this kind of minimum technology can large scale reduce the refrigerant the headache matter, moreover the smooth finish which processes in many applications very is also good. This domain

still had very many research to do, moreover the cutting tool company positively participated in such research was absolutely essential. If they will not do fall behind the competitor, will be at the disadvantageous position.

In the factory the special details design other perhaps better plan according to the world in. The manufacturing industry jobholders possibly still could ask why they do have to use recent development the technology to replace the refrigerant method diligently which the tradition already an experience number generation of person improved enhances, because implemented especially does the experiment and the defeat which the processing or the subarid processing produced possibly causes the higher short-term cutting tool cost. The concise answer is when the bit probably accounts for the model processing components cost 3%, the refrigerant cost (from purchases to maintenance, storage, processing) can account for the components cost 15%.

Perhaps does the dry processing is not all suits to each application, but above discusses likely other processing questions are same, needs from a wider operation, the environment and the commercial angle appraises. Will be able to help the cutting tool company which the customer will do this to have the competitive advantage, but these will not be able to provide unceasingly is in the passive position.

Cutting tool and nanotechnology

Can fiercely change the cutting tool industry the enchanting new do main is the miniature manufacture, or the processing small granule forms the product which needs. Must refer to is its here does not have about the cutting tool miniature manufacture first matter; Second must say the matter is it is not remote.

Why the miniature manufacture and are the cutting tool related. Because most main is the particle size smaller, the hard alloy toughness of material better also is more wear-resisting. (Some experts define with the nanometer level pellet for are smaller than 0.2 mu m, but other people persisted a nanometer pellet had to be smaller than the hard alloy tools prototype which 0.1 mu m) made already to complete and the test,It is said that wear resistant theatrically increase. The question is the nanometer level hard alloy pellet cannot depend on the smashing big material formation, they are certain through the smaller material constitution, but processes the molecular level granule is not easy and the economical matter.

切削加工新概念

现今的刀具公司再也不能只是制造和销售刀具,为了成功,他们必须与全球化制造趋势保持一致,通过提高效率、同客户合作来降低成本。在这个近乎瞬间的全球竞争的后NAFTA、后WTO时代,全世界的公司正对相同感觉作出更快、更轻、更便宜的反应。换句话说,他们制造的产品和零件包含能在高速下运转,由于成本的压力,最好、更轻而且要制造更便宜。取得这些目标的一个最佳途径是通过发展和应用新材料,但这些新的和改进的材料通常都难以加工。这种商业上的动力和技术上的困难的组合在汽车和航空工业尤其突出,并已成为有见识的刀具公司研发部门的首要驱动力。

例如,拿球墨铸铁来说,它已成为发动机零件和其它汽车、农用设备和机床工业上的零件的日益见的材料。这种合金提供较低的生产成本和良好的机械性能的组合。他们比钢材便宜,而比铸铁有更高的强度和韧性。但同时球墨铸铁非常耐磨,有快速磨坏刀具材料的倾向。这种耐磨性很大程度上受珠光体含量影响。某一已知球墨铸铁的珠光体含量越高,它的耐磨性越好,而且它的可加工性越差。另外,球墨铸铁的多孔性导致断续切削,这更加降低寿命。

可以预计,高硬度和高耐磨的切削材质需考虑球墨铸铁的高耐磨性。并且事实上材质包含极硬的TiC(碳化钛)或TiCN(碳氮化钛)的厚涂层在切削速度每分钟300米时加工球墨铸铁被证明通常是有效的。但是随着切削速度的增加,切屑/刀具结合面的温度也在增加。当发生这样的情况,TiC涂层倾向于和铁发生化学反应并软化,更多的压力作用在抗月牙洼磨损的涂层上。在这些条件下,希望有一种化学稳定性更好的涂层,如Al2O3(虽然在较低的速度下不如TiC硬或耐磨)。

化学稳定性比耐磨性更成为一个重要的表现性能分界的因素,速度和温度取决于被加工球墨铸铁的晶粒结构和性能。但是通常厚涂层的TiC或TiCN和仅有氧化物的较薄涂层是针对球墨铸铁应用的,因为今天大部分这类被加工材料的切削速度在每分钟150到335米之间。对于速度高于每分钟300米的应用,人们对这种材料是满意的。

为了使这个范围性能最优,山高研发和推出了针对球墨铸铁加工的材质TX150。这种材质有一个硬且抗变形的基体,对于加工球墨铸铁很理想。它的涂层由一层较厚的很耐磨的碳氮化钛和一层较薄的抗月牙洼磨损的氧化物涂层,顶面是一薄层TiN。这种涂层运用目前工艺水平的产生耐磨性和抗月牙洼磨损需要的CVD涂层的全部硬度而且韧性平滑性增加的中温化学气相沉积(MTCVD)工艺。基体/涂层的组合性能给予很高的抗塑性变形和刃口微崩能力,使之成为正常速度下加工球墨铸铁的理想材质。

涂层陶瓷也表现出能有效加工球墨铸铁。在过去,未涂层的韧性较好的诸如氮化硅和碳化硅纤维强化的氧化铝陶瓷应用受工件材料化学亲和性的限制。但是今天通过使用能抵抗切屑变形过程产生高热量的涂层刀具寿命已经显著增加。而某些早期这个领域的工件加工使用氧化铝涂层晶须强化陶瓷,今天的多数研究活动集中于TiN涂层氮化硅。这种涂层能显著拓宽

韧性较好的陶瓷的应用范围。

切削加工时,工件的已加工表面是依靠切削工具和工件作相对运动来获得的。按表面形成方法,切削加工可分为刀尖轨迹法、成形刀具法、展成法三类。

刀尖轨迹法是依靠刀尖相对于工件表面的运动轨迹,来获得工件所要求的表面几何形状,如车削外圆、刨削平面、磨削外圆、用靠模车削成形面等,刀尖的运动轨迹取决于机床所提供的切削工具与工件的相对运动;

成形刀具法简称成形法,是用与工件的最终表面轮廓相匹配的成形刀具,或成形砂轮等加工出成形面,如成形车削、成形铣削和成形磨削等,由于成形刀具的制造比较困难,因此一般只用于加工短的成形面;

展成法又称滚切法,是加工时切削工具与工件作相对展成运动,刀具和工件的瞬心线相互作纯滚动,两者之间保持确定的速比关系,所获得加工表面就是刀刃在这种运动中的包络面,齿轮加工中的滚齿、插齿、剃齿、珩齿和磨齿等均属展成法加工。有些切削加工兼有刀尖轨迹法和成形刀具法的特点,如螺纹车削。

切削加工质量主要是指工件的加工精度和表面质量(包括表面粗糙度、残余应力和表面硬化)。随着技术的进步,切削加工的质量不断提高。18世纪后期,切削加工精度以毫米计;20世纪初,切削加工的精度最高已达0.01毫米;至50年代,切削加工精度已达微米级;70年代,切削加工精度又提高到0.1微米。

影响切削加工质量的主要因素有机床、刀具、夹具、工件毛坯、工艺方法和加工环境等方面。要提高切削加工质量,必须对上述各方面采取适当措施,如减小机床工作误差、正确选用切削工具、提高毛坯质量、合理安排工艺、改善环境条件等。

提高切削用量以提高材料切除率,是提高切削加工效率的基本途径。常用的高效切削加工方法有高速切削、强力切削、等离子弧加热切削和振动切削等。

磨削速度在45米/秒以上的切削称为高速磨削。采用高速切削(或磨削)既可提高效率,又可减小表面粗糙度。高速切削(或磨削)要求机床具有高转速、高刚度、大功率和抗振性好的工艺系统;要求刀具有合理的几何参数和方便的紧固方式,还需考虑安全可靠的断屑方法。

强力切削指大进给或大切深的切削加工,一般用于车削和磨削。强力车削的主要特点是车刀除主切削刃外,还有一个平行于工件已加工表面的副切削刃同时参与切削,故可把进给量比一般车削提高几倍甚至十几倍。与高速切削比较,强力切削的切削温度较低,刀具寿命较长,切削效率较高;缺点是加工表面较粗糙。强力切削时,径向切削力很大故不适于加工细长工件。

振动切削是沿刀具进给方向,附加低频或高频振动的切削加工,可以提高切削效率。低频振动切削具有很好的断屑效果,可不用断屑装置,使刀刃强度增加,切削时的总功率消耗比带有断屑装置的普通切削降低40%左右。高频振动切削也称超声波振动切削,有助于减小刀具与工件之间的摩擦,降低切削温度,减小刀具的粘着磨损,从而提高切削效率和加工表面质量,刀具寿命约可提高40%。

对木材、塑料、橡胶、玻璃、大理石、花岗石等非金属材料的切削加工,虽与金属材料的切削类似,但所用刀具、设备和切削用量等各有特点。

木材制品的切削加工主要在各种木工机床上进行,其方法主要有:锯切、刨切、车削、铣削、钻削和砂光等。

塑料的刚度比金属差,易弯曲变形,尤其是热塑性塑料导热性差,易升温软化。故切削塑料时,宜用高速钢或硬质合金刀具,选用小的进给量和高的切削速度,并用压缩空气冷却。若刀具锋利,角度合适,可产生带状切屑,易于带走热量。

玻璃(包括锗、硅等半导体材料)的硬度高而脆性大。对玻璃的切削加工常用切割、钻孔、研磨和抛光等方法。对厚度在三毫米以下的玻璃板,最简单的切割方法是用金刚石或其他坚硬物质,在玻璃表面手工刻划,利用刻痕处的应力集中,即可用手折断。

对大理石、花岗石和混凝土等坚硬材料的加工,主要用切割、车削、钻孔、刨削、研磨和抛光等方法。切割时可用圆锯片加磨料和水;外圆和端面可采用负前角的硬质合金车刀,以10~30米/分的切削速度车削;钻孔可用硬质合金钻头;大的石料平面可用硬质合金刨刀或滚切刨刀刨削;精密平滑的表面,可用三块互为基准对研的方法,或磨削和抛光的方法获得。

刀具在热强合金中的应用

航空加工也变化迅速。例如,镍基高温合金如几年前多数人未听说过的Rene88现在占到航空发动机制造使用总金属量的10~25%。对于这个有很好的表现和商业理由。例如,这些热强合金能增加发动机寿命而且允许较小的发动机工作在大飞机上,那将提高燃烧效率并降低运营成本。这些韧性好的材料也把费用呈现在刀具上。它们的耐热性导致刀尖上的温度更高,从而降低了刀具寿命。相似地,这些合金里的碳化物颗粒显著增加了摩擦,从而缩短刀具寿命。

作为这些条件改变的结果,曾经能很满意地加工很多钛合金和镍基合金的硬质合金材质C-2在应用到当今的合金时遭受切削刃的压碎和切削深度线处严重的沟槽磨损。但是用最新的细颗粒硬质合金能有效加工高温合金,刀具寿命得到提高,更重要的是提高在高温合金应用时的可靠性。细颗粒硬质合金有比传统硬质合金材质更高的压缩强度和硬度,只是在韧性方面增加少量的成本。而结果是在高温合金加工上比传统硬质合金抵抗常见失效模式更有效。 PVD(物理气相沉积)涂层也被证明有效加工高温合金。TiN(氮化钛)PVD涂层是最早使用的并仍然是最受欢迎的。最近,TiAlN(氮铝化钛)和TiCN(碳氮化钛)涂层也能很好使用。过去TiAlN涂层应用范围和TiN相比限制更多。但是当切削速度提高后它们是一个很好的选择,在那些应用提高生产率达40%。另一方面,在较低的切削速度下取决于涂层的表面工况TiAlN会导致积屑瘤、随后的微崩和沟槽磨损。

近来,用于高温合金应用的材质已经发展了,这些涂层由几层组合而成。大量的实验室和现场测试已经论证了这种组合和其它任何一种单一涂层相比在很宽范围的应用时很有效。因

此针对高温合金应用的PVD复合涂层可能成为硬质合金新材质研发持续的焦点。和MTCVD涂层、涂层陶瓷集合在一起,它们有望成为更有效加工正在研发的新的更难加工工件材料的主要冲击力量。

干切削,包括冷却液在内的问题是刀具制造的科技和商业扩大产业化趋势的另一个领域。北美和欧洲严格冷却液管理的要求和最大的三家汽车制造商强制它们的核心供应商取得

ISO14000认证(ISO9000的环境管理版本),这使得冷却液处理成本上升。对汽车公司和他们核心供应商来说明显受欢迎的反应之一是在特定的加工应用里完全免除冷却液的使用。这种干加工的新世界给刀具供应商提出了一系列挑战。

最近,已经出现了一些有关这个专题揭示速度、进给、涂层化学成分和其它参数的很充实的综合性很强的有用的技术文章。在这里我想集中论述在操作和商业含义上的汽车制造商的新“干加工观点”。

金属加工从业人员能很好理解有关冷却液使用的问题,但大多数不能理解有关除在刀具-工件接触面间技术挑战(例如排屑)之外的干加工问题。通常可以观察到流出的冷却液分散切屑,但压力超过3000磅/英寸2的高速冷却液也能帮助断屑,特别是软且连续的切屑会引起刀具-工件接触面上的麻烦。

采用干切削工艺的零件的结果是机床比采用湿式加工零件的更热。你是否允许它们测量前在露天自然冷却?如果新加工的热零件经常放到周转箱,升高周围环境温度,是否零件充分冷却并正好足够允许精度检测?还有处置身边几十上百的零件会对操作工人增加额外负担。

同许多刀具/工件的技术问题一起,这些潜在的问题需要陈述是否干加工能行。幸运地,有很多途径阐述这些问题。例如,压缩空气被证明在很多应用里排屑成为问题的场合有成功的反响。

另一个方案是叫做MQL(最小量润滑)的技术,它由应用代替传统冷却液的相当少量油雾构成。这是一个公认的折中方案,这种最小量技术会大幅度减少冷却液的头疼事,而且在许多应用里加工出的光洁度也很好。这个领域仍然有很多研究在做,而且刀具公司积极参与这样的研究是绝对必要的。如果他们不做将落后于竞争对手,处于不利的地位。

根据世界上工厂内具体情况设计出别的也许更好的方案。制造业从业人员可能仍然会问为什么他们要努力使用新发展的技术代替传统的已经经历数代人改进提高的冷却液方法,尤其因为实施干加工或半干加工产生的试验和失败可能引起更高的短期刀具成本。简明的答案是当刀片大约占典型加工零件成本的3%时,冷却液的成本(从购买到维护、储存、处理)会占零件成本的15%。

干加工也许不是对每个应用都适合,但象上面讨论的其它加工问题一样,需要从更宽的操作、环境和商业角度来评价。能帮助客户这样做的刀具公司将有竞争优势,而那些不能提供的将不断处于被动地位。

刀具和纳米技术

一个能剧烈改变刀具工业的迷人的新领域是微型制造,或处理微小粒子形成所需的产品。要谈及的关于刀具微型制造的第一件事是它这里还没有;第二件要说的事是它并不遥远。

为什么微型制造和刀具相关。因为最主要的是颗粒尺寸越小,硬质合金材料韧性越好且更耐磨。用纳米级颗粒(一些专家定义为小于0.2μm,而其他人坚持纳米颗粒要小于0.1μm)制造的硬质合金刀具原型已经做好并测试,据称耐磨性戏剧性地增加。问题是纳米级的硬质合金颗粒不能靠粉碎较大的材料形成,它们一定得通过更小的材料构成,而处理分子级粒子还不是一件容易和经济的事情。

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History Of The Snowblower So who did invent the snowblower or snowthrower? We need to begin by qualifying that question since there are a number of answers depending on your interest. Some notable firsts would be: ●The first machine to clear snow by throwing or blowing it ●The first fully mobile snow clearing machine? ●The first domestic walk-behind snow blower The latter is the one people generally think of and have the most interest in. It is also the one that has the most elusive answer. Chapter 1 So where did it all begin? Looking back in time we need to consider where would there be a need to remove snow while having a source of power available? The need and the enabling power were found on the railways of the U.S. snowbelt and in Canada. The earliest documented art belongs to a Toronto dentist known as J/W Elliot. His 1869 patent #390 design was never built. The story next takes us to Orangeville Ontario, Canada where we find Orange Jull, a gristmill operator and inventor. In 1884 he applied for a patent and was subsequently granted patent #18506. Jull did not have the means to build and commercialize his invention so he contracted the local Leslie brothers to build the machines. The Jull/Leslie machines were self powered but not self propelled. A locomotive was used to move the machine. The Jull design consisted of 2 large inline fans rotating in opposite directions. The lead fan chewed into and pulverized the snow while blowing it back into the discharge fan, which propelled it into the sky. Due to clogging problems it was simplified to a single fan. Further changes to effectively control the discharge were made including a movable deflector and pitching impeller blades. Production was moved to the Cook locomotive works in several locations. Additional machines were built under license. Finally 5 machines were "home built" by end users with the last one finished in 1971. In all 146 were built. Later work consisted of fortifying the design to deal with the hazards of the unknown. Tracks were often blocked with fallen trees and other debris that were concealed in the snow. Legend has it that in one case a herd of cattle were trapped and buried under the snow on the rail bed. As the rotary snowplow progressed forward beefsteaks were flying. They remained in production into the 1950s and a few are still in service today. Many survive as museum pieces with an occasional demonstration. Following his collaboration with the Leslie Brothers Orange Jull went on to create a next generation machine. This design utilized a screw auger to collect the snow. It was not as effective,

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