机械表面加工质量外文文献翻译、中英文翻译

1、外文资料Mechanical face work qualityThe machine parts destruction, always starts generally from the surface layer.The product performance, in particular its reliability and the durability, are decided to a great extent by the components surface layer quality.Studies the machine-finishing surface quality

2、 the goal is in order to grasp in the machine-finishing each craft factor to process the surface quality influence the rule, in order to utilize these rules to control the processing process, finally achieved the improvement surface quality, enhances the product operational performance the goal.Just

3、 processed between the friction vice-two faying surface, the initial stage in the surface roughness peak department contact, the actual contacted area far was only smaller than the theory contacted area, in the peak department which contacted mutually has the extremely big unit stress, caused the ac

4、tual contacted area place to have the plastic deformation, the elastic deformation and the peak department between shearing failure, caused the serious attrition.The components wear may divide into three stages generally, the initial period attrition stage, the normal wear stage and the fierce attri

5、tion stage.The surface roughness the influence which wears to the components surface is very big.Said generally the surface roughness value is smaller, its wearability is better.But the surface roughness value too is small, the lubricating oil not easy to store up, between the contact face easy to h

6、ave the molecular cementation, wears instead increases.Therefore, contact face roughness has a best value, its value and components working condition related, when work load enlarge, the initial period wearing capacity increases, the surface roughness best value also enlarges.The processing surface

7、hammer-harden makes the friction subtabulation surface layer metal the microhardness to enhance, therefore may cause the wear resistant enhancement generally.But is not the hammer-harden degree will be higher, the resistance to wear is higher, this is because the excessive hammer-harden will cause t

8、he metal organization to be excessively loose, even will appear the crack and surface layer metal flaking, will cause the resistance to wear to drop.After metal the fatigue failure which is produced the alternating load function often occurs in the components surface and under the superficial chilli

9、ng level, therefore the components surface quality is very big to the fatigue strength influence.Under the alternating load function, the surface roughness saddle spot easy to set up stresses the centralism, produces the fatigue cracking.The surface roughness value is bigger, the superficial grain m

10、ark is deeper, the grain bottom radius is smaller, anti-fatigue failure bottom ability is worse.The residue stress is very big to the components fatigue strength influence.The surface layer remaining tensile stress will make the fatigue cracking to expand, acceleration fatigue failure; But the surfa

11、ce layer residual stress can prevent the fatigue cracking the expansion, delays the fatigue failure the productionThe surface chilling is accompanied by the residual stress generally the production, may prevent the crack has and prevents to have the crack expansion, to enhances the fatigue strength

12、to be advantageous.The components corrosion resistance is decided to a great extent by the surface roughness.The surface roughness value is bigger, then in the saddle accumulates the corrodent to be more.The corrosion resistance is worse.The surface layer remaining tensile stress can have the stress

13、 corrosion dehiscence, reduces the components the resistance to wear, but the remaining compressed stress can prevent the stress corrosion dehiscence.The surface roughness value size will affect the mating surface the coordinate quality.Regarding the gap coordination, roughness value congress caused

14、 the attrition enlarge, the gap to increase, destroyed the request coordinate nature.Regarding the full coordination, in the assembly process a part of superficial raised peak has been pushed evenly, the actual full quantity has reduced, reduced the coordination joint strength.The cutting tool is op

15、posite when makes the feed motion in the work piece, in the processing surface has left behind the layer of cutting residual area, when its shape the cutting tool geometry shape duplicate reflects.Reduces to feed quantity, the host angle of deflection, the vice-angle of deflection as well as increas

16、es the knife point circular arc radius, may reduce the residual area the altitude.In addition, suitably increases the cutting tool the front rake reduces when the cutting the plastic deformation degree, the production which chooses the lubricant reasonably and improves the cutting tool sharpening qu

17、ality to reduce when cutting the plastic deformation and the suppression built-up edge, the scale punctures, also is reduces the surface roughness value the effective action.When processing plastic material, has had the plastic deformation by the cutting tool to the metal extrusion, adds avulsion fu

18、nction which the cutting tool force scrap and the work piece separate, causes the surface roughness value enlarge.The work piece toughness of material is better, the metal plastic deformation is bigger, the processing surface is rougher.When processing brittle material, its scrap assumes garrulously

19、 granular, but leaves behind many hemp spots as a result of the scrap disintegration in the processing surface, causes the surface roughness.When direct positive machining the surface roughness forming process is same, abrasive machining surface roughness formation also when decides by the geometry

20、factor and the superficial metal plastic deformation.The influence grinding surface roughness primary factor includes: 1、Grinding wheel granularity 2、Grinding wheel degree of hardness 3、Grinding wheel conditioning 4、Grinding speed 5、The grinding radial feed quantity and the light rub the number of t

21、imes 6、Work piece circular feed speed and axial feed quantity 7、Cooling lubricant In machining, work piece because receives the cutting force and cuts the hot function, causes the surface layer metal the physical mechanical property to have the change, the most main change is the surface layer metal

22、 microhardness change, the microstructure change and the residual stress production.Because time abrasive machining produces the plastic deformation and cuts hotly the knife edge cutting when is more serious than, thus the abrasive machining postprocessing surface layer above three physics mechanica

23、l property change can be very big. In because the machine-finishing process the cutting action of force produces the plastic deformation, causes the crystal lattice distortion, the distortion, intergranular has the cutting slipping, the crystal grain is elongated with the fibrosis, even stave, these

24、 all can cause the surface layer metal degree of hardness and the intensity enhances, this kind of phenomenon is called the hammer-harden (or is called strengthening).The surface layer metal strengthens the result, can increase the flow of metal the resistance, reduces the metal the plasticity, the

25、metal physical property also can change.Is been at the high energy position by the hammer-harden metal the non-steady state, as soon as only then has the possibility, the metal non-steady state must to the quite stable condition transformation, this kind of phenomenon is called the attenuation.The a

26、ttenuated function size is decided by the temperature height, the temperature duration length and the strengthened degree size.Because the metal simultaneously receives the strength and the hot function in the machine-finishing process, therefore, after the processing the surface layer metal final n

27、ature is decided by strengthened and the attenuated combined action result.The evaluation hammer-harden target has three items, namely surface layer metal microhardness HV, hardened level depth h and hardenability N.The cutting edge obtuse radius increases, strengthens to the surface layer metal ext

28、rusion function, the plastic deformation intensifies, causes the chilling enhancement.After the cutting tool the knife surface attrition increases, the latter knife surface with is processed superficial the friction aggravating, the plastic deformation increases, causes the chilling enhancement.The

29、cutting edge obtuse radius increases, strengthens to the surface layer metal extrusion function, the plastic deformation intensifies, causes the chilling enhancement.After the cutting tool the knife surface attrition increases, the latter knife surface with is processed superficial the friction aggr

30、avating, the plastic deformation increases, causes the chilling enhancement.When is rubbed the work piece surface layer temperature to achieve when above transformation temperature, the surface layer metal has the microstructure change, causes the surface layer metal intensity and degree of hardness

31、 reduces, and is accompanied by the residual stress production, even appears the microscopic crack, this kind of phenomenon is called the grinding burn.If the grinding area temperature has not surpassed the chilled steel the transformation temperature, but has surpassed the martensite the transition

32、 temperature, the work piece surface layer metal tempered martensite organization transforms degree of hardness low tempering organization (sorbite or troostite), this kind of burn is called the tempering burn.If the grinding area temperature has surpassed the transformation temperature, in addition

33、 the refrigerant sharp quenching function, the surface layer metal has two quenching, causes the surface layer metal to appear two quenching martensite organization, its solidity ratio original tempered martensite high, in its lower level, because cools slowly, appeared the solidity ratio original t

34、empered martensite low tempering organization (sorbite or troostite), this kind of burn is called the quenching burn.If the grinding area temperature has surpassed the transformation temperature, but the grinding region does not have the refrigerant to enter, the surface layer metal will have the an

35、nealing organization, the skin hardness suddenly drops, this kind of burn will be called the annealing burn.The grinding heat is creates the grinding burn the root, therefore improvement grinding burn by two ways: One is reduces the grinding to produce hotly as far as possible; Two, the improvement

36、cooling condition, causes to have the quantity of heat as far as possible little to spread to the work piece.1、Chooses the grinding wheel correctly 2、Reasonable choice cutting specifications 3、Improvement cooling condition 4、When cutting has the plastic deformation occurrence in the processing surfa

37、ce conductive sea, causes the superficial metal the specific volume enlargeBecause the plastic deformation only produces in the surface layer metal, but the surface layer metal specific volume increases, the volume expansion, needs to receive inevitably with its connected in level metal impediment,

38、therefore on has had the residual stress in the superficial conductive sea, but has the remaining tensile stress in level metal. In the machining, the cutting district conference has the massive cutting hot production, the different microstructure has the different density, also has the different sp

39、ecific volume, if the surface layer metal has had the microstructure change, the surface layer metal specific volume change needs to receive inevitably with it connected substrate metal hindrance, thus has the residual stress production. La perfection de composants charge le choix final extrieur de

40、mthode de transformation de mthode de travail est trs importante, parce que la mthode de travail finale reste derrire dans ce visage actif que leffort rsiduel directement affectera la pice de machine lexcution oprationnelle.La perfection bien choisie de composants charge la mthode de transformation

41、finale extrieure de mthode de travail, doit considrer ceci des composants que la perfection charge extrieur la condition de travail concrte et la forme possible de destruction.中文译文机械表面加工质量机械零件的破坏，一般总是从表面层开始的。产品的性能，尤其是它的可靠性和耐久性，在很大程度上取决于零件表面层的质量。研究机械加工表面质量的目的就是为了掌握机械加工中各种工艺因素对加工表面质量影响的规律，以便运用这些规律来控制加

42、工过程，最终达到改善表面质量、提高产品使用性能的目的。一个刚加工好的摩擦副的两个接触表面之间，最初阶段只在表面粗糙的的峰部接触，实际接触面积远小于理论接触面积，在相互接触的峰部有非常大的单位应力，使实际接触面积处产生塑性变形、弹性变形和峰部之间的剪切破坏，引起严重磨损。零件磨损一般可分为三个阶段，初期磨损阶段、正常磨损阶段和剧烈磨损阶段。表面粗糙度对零件表面磨损的影响很大。一般说表面粗糙度值愈小，其磨损性愈好。但表面粗糙度值太小，润滑油不易储存，接触面之间容易发生分子粘接，磨损反而增加。因此，接触面的粗糙度有一个最佳值，其值与零件的工作情况有关，工作载荷加大时，初期磨损量增大，表面粗糙度最佳值

43、也加大。加工表面的冷作硬化使摩擦副表面层金属的显微硬度提高，故一般可使耐磨性提高。但也不是冷作硬化程度愈高，耐磨性就愈高，这是因为过分的冷作硬化将引起金属组织过度疏松，甚至出现裂纹和表层金属的剥落，使耐磨性下降。 金属受交变载荷作用后产生的疲劳破坏往往发生在零件表面和表面冷硬层下面，因此零件的表面质量对疲劳强度影响很大。 在交变载荷作用下，表面粗糙度的凹谷部位容易引起应力集中，产生疲劳裂纹。表面粗糙度值愈大，表面的纹痕愈深，纹底半径愈小，抗疲劳破坏底能力就愈差。余应力对零件疲劳强度的影响很大。表面层残余拉应力将使疲劳裂纹扩大，加速疲劳破坏；而表面层残余应力能够阻止疲劳裂纹的扩展，延缓疲劳破坏的

44、产生表面冷硬一般伴有残余应力的产生，可以防止裂纹产生并阻止已有裂纹的扩展，对提高疲劳强度有利。 零件的耐蚀性在很大程度上取决于表面粗糙度。表面粗糙度值愈大，则凹谷中聚积腐蚀性物质就愈多。抗蚀性就愈差。表面层的残余拉应力会产生应力腐蚀开裂，降低零件的耐磨性，而残余压应力则能防止应力腐蚀开裂。 表面粗糙度值的大小将影响配合表面的配合质量。对于间隙配合，粗糙度值大会使磨损加大，间隙增大，破坏了要求的配合性质。对于过盈配合，装配过程中一部分表面凸峰被挤平，实际过盈量减小，降低了配合件间的连接强度。刀具相对于工件作进给运动时，在加工表面留下了切削层残留面积，其形状时刀具几何形状的复映。减小进给量、主偏角

45、、副偏角以及增大刀尖圆弧半径，均可减小残留面积的高度。此外，适当增大刀具的前角以减小切削时的塑性变形程度，合理选择润滑液和提高刀具刃磨质量以减小切削时的塑性变形和抑制刀瘤、鳞刺的生成，也是减小表面粗糙度值的有效措施。加工塑性材料时，由刀具对金属的挤压产生了塑性变形，加之刀具迫使切屑与工件分离的撕裂作用，使表面粗糙度值加大。工件材料韧性愈好，金属的塑性变形愈大，加工表面就愈粗糙。加工脆性材料时，其切屑呈碎粒状，由于切屑的崩碎而在加工表面留下许多麻点，使表面粗糙。正像切削加工时表面粗糙度的形成过程一样，磨削加工表面粗糙度的形成也时由几何因素和表面金属的塑性变形来决定的。影响磨削表面粗糙的主要因素有：1、砂轮的粒度 2、砂轮的硬度 3、砂轮的修整 4、磨削速度 5、磨削径向进给量与光磨次数