外文翻译---关于硬质合金刀具刀刃磨损的研究.doc

study on boundary notch of cementecarbide cutting tool1wang guicheng, pei hongjie, li qinfeng , zhang chun jiangsu university, zhenjiang, jiangsu, 212013 chinaabstract the performance of cemented carbide cutting tools directly influence machining quality of the machined workpiece .in this paper, the forming mechanism of boundary notch of cemented carbide cutting tool is studied, related theories analyzed, a definition of the boundary notch size presented, and main factors to influence boundary notch of tool pointed out. besides forming process and change lay of the boundary notch of tool are found out, and a certain number of measures to decrease and control the boundary notch of tool have been advanced.key words boundary notch; cemented carbide cutting tool; cutting burr; corner radius; tool cutting edge angle1 introductionthe wear and boundary notch of cemented carbide cutting tools are often found in the machining. they directly influence machining quality of the machined workpiece and the cutting performance and life of the cutter. especially, in the precision machining, flexible manufacturing system (fms) and other automation manufacture, wear and boundary notch behaviors of cemented carbide tools are even more important. metal cutting experiences have expounded that wear and boundary notch of the cemented carbide cutting tools are more serious in the machining of the workpiece in which the strain hardening is high and the remaining is not even. it seriously influences the machining quality of the machined piece and the cutting performance and life of the cutter. but, so far, there has not been much research on the boundary notch mechanism of cemented carbide cutting cutter, and the technical measures to reduce boundary notch of cemented carbide cutting tools are fewer1,2. so that, the based on the machining experiments of friction welded joint, this research focuses on the forming processes and main rules of the boundary notch, and has developed several measures to resist or lessen boundary notch, which provides a theoretical and experimental base to ensure cutting performances of cutters and machining quality.2 the forming process and main size of boundary notchthe boundary notch of cemented carbide cutting tools is a wear area, which is relatively large, resulting from friction between main cutting edge and the surface of the workpiece as the following fig.1. fig.1 (a) shows a traditional wearing type of the flank. the rake face ar and flank face aa are also shown. fig.1 (b) shows the main dimension of boundary notch of the lathe tool, in which vn represented the height of boundary notch and c refers to the width. it is apparent that the greater the dimensions of vn and c are, the greater it destroys the performance of tools and influences the machining quality3,4.by experiment, the forming process of the boundary notch can be divided into the following three steps: firstly, several micro cracks are produced at main cutting edge. secondly, the mesh fractures are found in the boundary areas and they will spread. finally, the piece material will be denuded and the boundary notch is formed. in the subsequent cutting process, the dimension of the boundary becomes bigger and bigger.fig. 2 shows the forming process of boundary notch of the cemented carbide cutting tools.main factors to influence boundary notch are mechanical performance of the piece material, the cutter material, and geometry parameter of the cutter. the following experiments were carried out in order to expound the forming mechanism and evolution rules of the boundary notch.fig. 1 boundary notch of the cemented carbide cutting tool in turningfig.2 forming process of boundary notch of the cemented carbide cutting tools.3 experiment conditions and testing measuresthe lathe c6130 and reversible cutting tool are used in the experiment. five cutter materials are employed. main mechanical parameters of cutter material are shown in table 1.the machining piece is the friction-welded line of the single hydraulic pillar. the width of the welded line is 15mm and the machining allowance is 5.5mm. besides, the above pillar is welded with 270simn and 45# steel. the relatively mechanical performances of the welded line are shown in table 2.based on manufacturing experience and relative information in china and other countries about similar machining process, the chosen machining and tool geometry parameters are shown in table 3.the boundary notch dimensions of the cemented carbide cutting tools (boundary notch height vn and width c are directly attained by tool microscope. in order to ensure reliability of the results, repeated experiments are carried out. the recurrent performance is good.4 experiment results and analysis4.1 cutter materialsfor different cutter materials, as shown in fig. 3, the machining performance and the ability to resist boundary notch are distinctly different.from fig. 3, we can find the boundary notch dimensions are relatively large when yd10,yd15 and yw are used. whereas the boundary notch dimension is smallest when yts25 is used. because of the asymmetry allowances impacts and vibrations will take place. yts25 cutter has better impact-resisting performance and boundary notch dimension. therefore, yts25 cutter material is selected to do the following experiments.table 1 material performances of cutterstypematerial performanceremarkhrab(kg/mm2)(g/cm2)yd10yd15707yw2yts259290.592919113012514515020012.4112.811.512.111.812.512.71.3.312.813.2north toolsnorth toolszigongzhugongzhuzhoutable 2 mechanical performances of cuttersitemtensile strengthelongation rateshrinkage rateimpact toughnessb(kg/mm2)(%)t(%)k(kg/cm2)270simn1001240545#6116405welding line64.6825.5 1337.646.23.56.4table 3 cutting parameterscutting velocity v (m/min) 75cutting depth p (mm)5.5feed rate f(mm/r)0.3rake angle 0 ( 10clearance angle 0 (8cutting edge angle kr (845 ; 75 ; 90edge inclination s (-5negative chamfer b1 (mm)0.1; 0.2; 0.3cutter corner radius r(mm) 0.2; 0.4; 0.84.2 influences of cutting edge anglethe results of the variety boundary notch are shown as in fig. 4 when the cutting edge angle is changed. from fig. 4 we can find that, with the lessening of the cutting edge angle kr , the dimensions of the boundary notch decrease. the reason is that with the lessening of the cutting edge angle kr , the length of the cutting edge that acts on cutting becomes larger and the average loads on the cutting edge become lighter.4.3 influences of cutter corner radius rthe results of the variety boundary notch with the cutter corner changing are shown as fig. 5.the boundary notch dimension decreases with the cutter corner radius r becoming lesser. the reason is that with the increasing of the cutter corner radius, the impact-resistance performance.fig. 3 different boundary notch results to different utter materialfig. 4 influences of cutting edge angle krincreases and the volume of the cutter that endures heat becomes larger. therefore, under the same cutting conditions, boundary notch dimensions (vn, c) decrease when the cutter corner radius becomes lesser.4.4 influences of negative chamfer blthe experiment results of the variety boundary notch are shown as in fig. 6 when the width of the negative chamfer is changed. the dimension of the boundary notch will decrease when the width of the negative chamfer bl decreases. therefore, in order to resist or decrease the cutter boundary notch, the lesser negative chamfer bl should be chosen.4.5 deburring machining processthe burrs have some influences on cutter boundary notch in metal machining process. a deburring cutter is chosen to decrease the adverse influence on cutter. a different result between deburring machining process and common machining process is shown as in fig. 7. it can be seen that about 75% of the boundary notch is decreased. so, burr is a main factor to produce and increase the boundary notch of the cutter.fig.5 influence of cutter corner radius rfig.6 influences of negative chamfer widthfig.7 deburring machining process and common machining process5 conclusionsfrom above experimental research and theoretical analysis, the following conclusions are attained:1) boundary notch of the cutting tool can be expressed by boundary notch height vn and boundary notch width c. the forming processes of boundary notch can be divided into three steps:micro-tipping appears firstly; then, mesh fractures expand; finally, boundary notch results.(2) main factors that influence boundary notch of cemented carbide cutter are piece material,cutter material and cutter geometry parameters.(3) deburring machining process and adjusting cutting tool geometry parameters (to reduce edge angle kr and width of negative chamfer bl, to increase cutter corner radius r) can be chosen to decrease effectively boundary notch, which ensures the quality of workpiece and cutting performances of cutting tool.acknowledgementsthe authors are grateful to natural science foundation of p.r.c. for support of this project(grant no. 59775071 and 50275066).references1 wang guicheng. inner stress in the surface of brazed cemented carbide cutting tool.cemented carbide.1989,6(4):p.169172(in chinese)2 wang guicheng. cutting performances of brazed cemented carbide cutting tool. cemented carbide. 1993, 10(1):p.6972(in chinese)3 zhou zehua. the principles of metal cutting. shanghai: shanghai science and technology press,1985(in chinese)4 zhang youzhen. metal cutting theory. beijing: aviation industry press, 998(in chinese)关于硬质合金刀具刀刃磨损的研究王桂城，裴鸿杰，李庆丰，张春江苏大学，中国江苏镇江摘要 硬质合金刀具的性能直接影响到工件的切削质量。在这篇文章里，研究了刀具磨损的形成机制，分析相关理论，提出了刀具磨损尺寸的定义，并且指出了刀具磨损的主要因素。除硬质合金刀具的形成过程和变动位置以外发现, 并且一定数量的措施减少和控制硬质合金刀具被推进了。关键词 刀刃磨损；硬质合金刀具； 切口毛刺； 角落半径； 工具切断边缘角1.介绍硬质合金刀具的刀刃的磨损在加工中经常发现。它们直接地影响以机器制造的工件和切削质量和刀具的寿命。尤其,在精密机加工中,柔性制造系统(fms)和硬质合金刀具的其他自动化制造系统中，擦损和刀刃磨损轨迹更重要。金属制的痕迹已经解释了擦损和硬质合金刀具的刀刃磨损在工件的机加工在高应变硬化中哪一个更严重和甚至没有剩余的情况。它严重地影响机器制造的工件质量和切断的性能和刀具的寿命。但是，迄今为止，在硬质合金刀具的刀刃磨损机构和专门技术措施上，都使硬质合金刀具的界线凹槽变得越来越小。因此,以磨擦熔接接合的机制实验为基础,这一个研究把重心集中在刀刃磨损的形成程序和干管尺,而且已经发展数个的措施抵抗或者减小界线凹槽,这提供一个理论上的和经验性的碱确保刀具的切断性能和切削质量。2 刀刃磨损形成原因和主要尺寸硬质合金刀具的磨损是一个擦损面积,是相对地大的,由于主要的刃口和工作件的表面之间的磨擦，如图1所示。图1(a)显示了传统侧面的磨损类型,ar倾斜面 ar 和侧面aa面在如图1(b)中也显示。显示车刀的凹槽的主要尺寸,和的刀刃磨损，在车床中vn代表刀刃磨损的高度。c代表它的宽度，这样看起来，vn和c的尺寸越大，那么它破坏刀具工具的性能和影响机制质量的机会越大。根据实验, 刀刃磨损的形成方法被分成三步: 第一，数个的微观裂解在主要的刃口被提出展现。 第二, 网眼破面在界线面积和他们被发现将会扩展。 最后，块材料将会被使裸露，而且凹槽被形成。 在后成的切削过程中，刀刃磨损的尺寸会变得越来越大。图1 侧刀面的磨损类型图2 硬质合金刀具和刀刃磨损的形成原因影响刀刃磨损的主要因素是刀具的材料的机械性能，刀具材料和几何参数。 下列的实验操作是为了解释边界尺寸的形成机理和刀具磨损的扩展尺寸。3 实验条件和测试措施车床 c6130 和可逆刀具在实验被使用。 五种刀具材料被使用。刀具材料的主要机械参数如表1。机制块是单一状柱的磨擦焊接线。 被焊接的线的宽度是 15个毫米，而且切削裕度是 5.5毫米。此外，上述的柱形物是用270simn和 45#钢一起焊接。被焊接的线的相对机械性能在表2被显示。在类似物机制方法中国和其他的国家中以制造业的经验和有关情报上,被选择的机制和工具几何参数在表 3被显示。硬质合金刀具的边界凹槽尺寸(界线凹槽高度vn 和宽度c由工具得到。为了要确保结果的可靠度, 反复的实验被实行。 再利用的性能很好。4 实验结果分析4.1 刀具材料对于不同的刀具材料,如图3所示,机制性能和刀刃磨损的抵抗能力是显然地不同的。从图3,我们能找刀刃磨损尺寸是相对地的大，当yd10,yd15和yw 被使用的时候。然而当 yts25被使用的时候，刀刃磨损尺寸很最小。因为不对称现象公差挤入，而且振动将会发生。 yts25 刀具有得更好抗拒碰撞的性能和刀刃磨损尺寸。 因此, yts25 刀具材料被选择做跟随实验。表1切削刀具的材料性能类型材料性能标记hrab(kg/mm2)(g/cm2)yd10yd15707yw2yts259290.592919113012514515020012.4112.811.512.111.812.512.71.3.312.813.2north toolsnorth toolszigongzhugongzhuzhou表2 切削刀具的机械性能代号抗拉强度伸长率伸缩率冲击韧性b(kg/mm2)(%)t(%)k(kg/cm2)270simn1001240