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带减摩槽刀片切削机理的研究 总被引:2,自引:2,他引:0
对带减摩槽刀片的切削机理进行了理论研究,考察了减摩槽对主切削力(FZ)以及切削变形和断屑性能的影响,在此基础上得出三维断屑槽设计的一些有益结论,并通过平前刀面刀片和带减摩槽刀片的对比切削试验验证了这些结论,最后据此设计了一种新型断屑槽。 相似文献
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通过ABAQUS有限元软件分别对梯形、直线圆弧型和梯形双槽结构断屑槽刀具切削Ti6Al4V钛合金材料进行三维切削仿真,并分析其切削力的波动,得到断屑槽槽型在控制切屑卷曲过程中对刀具在主运动方向、进给方向和切削深度方向振动的影响。经过仿真发现,梯形、直线圆弧型和梯形双槽结构断屑槽在控制切屑卷曲的过程中对刀具振动的影响各不相同。三种槽型结构中,梯形断屑槽刀具的振动最弱,直线圆弧型断屑槽刀具的振动最强。 相似文献
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《工具技术》2021,(9)
针对微织构刀具加工过程中的衍生切削效应,利用正交微切削单元开展了微坑刀具及无织构刀具的钛合金微切削实验,从切屑底面形貌、微坑黏结状态等方面分析了微坑刀具微切削性能;通过ABAQUS软件对微织构刀具微切削钛合金过程进行有限元模拟,分析微坑织构的衍生切削作用对刀-屑接触应力分布及切削力的影响,优化设计微坑边缘过渡区参数并进行切削仿真分析。实验和仿真结果表明,微坑会减小前刀面黏结,存储微屑,减小刀-屑接触应力,提高刀具减摩性能;但微坑与切屑的衍生切削作用会增大瞬时切削力,降低切削过程平稳性。此外,微坑过渡区优化可改善切削过程波动,降低切削力,改变切屑形态,改善切屑在微坑的流入/流出状态,有助于减小微坑织构衍生切削效应,提高织构的减摩效果。 相似文献
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为研究断屑槽槽背的几何形状对车削加工的影响,选用硬质合金和钛合金为研究对象,基于ABAQUS有限元软件建立三维切削仿真模型,通过单因素实验法研究了三种不同断屑槽槽背对切削力、切削热和切屑卷曲程度等的影响。结果表明:在实验参数的范围内,柱面型槽背刀具较单斜面型、斜面和柱面组合型槽背刀具的切削性能更好;柱面型槽背刀具切削所形成切屑的塑性应力、应变更低,切削过程更加平稳,有利于提高工件表面质量及刀具的使用寿命。 相似文献
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为有效缩短现有断屑槽刀具的设计周期、降低设计成本,采用有限元方法模拟了切削过程中切屑折断过程。利用Solid Works软件建立了三种刀具的三维模型,并在Deform 3D软件中对车削45钢工件过程进行了三维切削仿真。其中,工件材料采用了Johnson-Cook模型和Cockroft-Latham韧性断裂准则,仿真模型采用了有效参数设置以保证数值计算精度与效率。通过仿真研究了不同切削参数下的切屑形态、断屑过程及主切削力等。研究结果表明,仿真结果与试验结果吻合良好,该仿真模型及方法能有效应用于断屑槽刀具断屑性能研究,是三维复杂断屑槽刀具设计和切削参数优化的一种新方法。 相似文献
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张翰潮 《机械工人(冷加工)》1992,(6)
为什么在刀片的前面上有一个槽呢?是为了断屑。在研究或选择刀片槽形时,不单要考虑断屑,还要考虑该种槽形对主切削刃的磨损,切削力的大小,切屑是否飞溅等因素。随着我国机械加工技术的提高与发 相似文献
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高速切削30CrNi3MoV淬硬钢切屑形成机理的试验研究 总被引:3,自引:0,他引:3
通过30CrNi3MoV淬硬钢的高速切削试验,观察和测量不同切削条件下切屑形态的演变过程、锯齿状切屑形成的临界切削条件、切削力.结果表明,切削速度和刀具前角是影响切屑形态和切削力的主要因素,随着切削速度的提高,在某一临界切削速度下,切屑形态由带状屑转变为锯齿状切屑,随着刀具前角由正前角逐渐变为负前角,临界切削速度明显减小,当锯齿状切屑形成时,切削力大幅度降低.使用金属切削过程中绝热剪切临界切削条件判据对锯齿状切屑形成临界切削速度预测的结果表明,锯齿状切屑形成的根本原因是主剪切区内发生周期性的绝热剪切断裂. 相似文献
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Wu Ze Deng Jianxin Chen Yang Xing Youqiang Zhao Jun 《The International Journal of Advanced Manufacturing Technology》2012,62(9-12):943-951
Surface textures were made using laser on the rake or flank face of the cemented carbide (WC/Co) inserts. Molybdenum disulfide solid lubricants were filled into the textured grooves to form self-lubricating textured tools. Dry cutting tests on Ti-6Al-4V were carried out with these self-lubricating textured tools and conventional tool. The machining performance was assessed in terms of the cutting forces, cutting temperature, chip thickness ratio, friction coefficient at the tool–chip interface, and tool wear. Results show that the cutting forces and cutting temperature of the self-lubricating textured tools were reduced compared with that of the conventional tool. The application of the self-lubricating textured tool with elliptical grooves on its rake face can reduce the tool–chip friction coefficient and the chip thickness ratio. The tool life of the textured tools is improved compared with that of the conventional tool. The effectiveness of the self-lubricating textured tools in improving cutting performance is related to the cutting parameter. 相似文献
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刀具切削钛合金时存在切削温度高、单位面积上切削力大等问题,微织构刀具可以有效减小摩擦力,减小切削力。通过正交实验法设计微织构参数,研究微织构参数对Al 2O 3/La 2O 3/(W,Mo)C无黏结相硬质合金刀具以及YG8刀具切削钛合金实验的切削性能影响。实验结果表明,合适参数的沟槽型微织构能有效降低Al 2O 3/La 2O 3/(W,Mo)C无黏结相硬质合金刀具和YG8刀具切削TC4钛合金的切削力,相同沟槽参数下,无黏结相硬质合金刀具的切削力明显低于YG8刀具的切削力;合适参数的沟槽型微织构能有效降低刀具刀屑界面的摩擦系数,相同沟槽参数下,无黏结相硬质合金刀具的摩擦系数大都低于YG8刀具的摩擦系数;沟槽深度10μm、沟槽间距100μm以及沟槽宽度30μm的沟槽参数下,切削钛合金时,无黏结相硬质合金刀具前刀面无明显磨损,后刀面只有边界磨损,YG8刀具发生崩刃,前刀面出现切屑的滞留。 相似文献
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Chunhui Ji Jing Shi Yachao Wang Zhanqiang Liu 《The International Journal of Advanced Manufacturing Technology》2013,68(1-4):365-374
The interaction between the tool rake face and the chip is critical to chip morphology, cutting forces, surface quality, and other phenomena in machining. A large body of existing literature on nanometric machining or nano-scratching only considers the overall friction behavior by simply regarding the total force along tool movement direction as the friction force, which is not suitable for describing the intriguing friction phenomena along the tool/chip interface. In this study, the molecular dynamic (MD) simulation is used to model the nanometric machining process of single crystal copper with diamond tools. The effects of three factors, namely, tool rake angle, depth of cut, and tool travel distance, are considered. The simulation results reveal that the normal force and friction force distributions along tool/chip interface for all cases investigated are similarly shaped. It is found that the normal force consistently increases along the entire tool/chip interface when a more negative rake angle tool is used. However, the friction force increases as the rake angle becomes more negative only in the contact area close to the tool tip, and it reverses the trend in the middle of tool/chip interface. Meanwhile, the increase of depth of cut overall increases the normal force along the tool/chip interface, but the friction force does not necessarily increase. Also, the progress of tool into the work material does not change the patterns of normal force, friction force, or friction coefficient distributions to a great extent. More importantly, it is discovered that the traditional sliding model with a constant friction coefficient can be used to approximate the later section of friction distributions. However, no friction model for traditional machining is appropriate to describe the first section of friction distributions obtained from the MD simulation. 相似文献
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Yunsong Lian Jianxin Deng Guangyuan Yan Hongwei Cheng Jun Zhao 《The International Journal of Advanced Manufacturing Technology》2013,68(9-12):2033-2042
This paper proposes a new effective dry cutting tool named tungsten disulfide (WS2) soft-coated nano-textured self-lubricating tool which is fabricated by two steps. First, nano-texture is made on the tool–chip interface of rake face of uncoated YS8 (WC + TiC + Co) cemented carbide cutting inserts by femtosecond laser micromachining technology. Second, WS2 soft coating is deposited on the nano-textured tool by medium-frequency magnetron sputtering, multi-arc ion plating and ion beam assisted deposition technique. Dry turning tests on 45# quenched and tempered steel were carried out with three kinds of cutting tools: conventional YS8 tool, nano-textured tool (CFT), and WS2 soft-coated nano-textured self-lubricating tool (CFTWS). Results show that the cutting forces, cutting temperature, the friction coefficient at the tool–chip interface, and the antiadhesive effect of the nano-textured tools were significantly reduced compared with those of the conventional one. The CFTWS tool had the best cutting performance among all the tools tested under the same test conditions. Through cutting force and cutting temperature theoretical analysis and experimental results, four mechanisms responsible were found. The first one is explained as the formation of the WS2 lubricating film with low shear strength at the tool–chip interface, which was released from the surface nano textures and smeared on the rake face, and served as lubricating additive during dry cutting processes to reduce the cutting forces and cutting temperature. The second one is explained by the reduced contact length at the tool–chip interface of the nano-textured tools; the smaller direct contact area between the chip and tool rake face leads to less friction force, which can also contribute to the decrease of cutting forces and cutting temperature. The third one can be explained that because of the excellent lubricity of the WS2 lubricating film, the antiadhesive effect can be significantly improved which can reduce adhesive wear of the cutting tool and prolong the tool life. The fourth one can be explained that the advantage of CFTWS tool in cutting forces and cutting temperature is obvious in relatively high-speed and high-temperature conditions may be because of ultra-low friction coefficient, high temperature resistance, and the high oxidation resistance of WS2 soft coating which is not sensitive to high cutting temperature and high cutting speed can significantly improve the severe dry cutting environment. 相似文献
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基于大型有限元软件ABAQUS仿真平台,建立了高速加工的有限元模型。该模型采用Johnson—Cook(JC)模型作为工件材料模型,采用JC破裂模型作为工件材料失效准则,刀-屑接触摩擦采用可自动识别滑动摩擦区和黏结摩擦区的修正库仑定律,并采用任意拉格朗日一欧拉方法实现切屑和工件的自动分离。通过有限元方法对AISI4340(40CrNiMoA)淬硬钢高速直角切削过程进行了数值模拟。通过改变刀具前角的大小,对高速硬态切削过程中刀具的温度场及切削力的动态变化进行了研究,探讨了它们各自的变化规律,研究结果有助于优化高速切削工艺,研究刀具磨损机理和建立高速切削数据库。 相似文献
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通过预测加工304不锈钢时产生的切削力,从而对切削参数和刀具几何参数进行优化,是提高304不锈钢的加工精度、切屑控制及保障刀具寿命的基础。建立304不锈钢切削仿真模型,为提高模型的精确性,选择Johnson-Cook本构方程和黏结-滑移摩擦模型。结果表明:采用黏结-滑移摩擦模型的切削力预测结果更为准确,表明相对于纯剪切摩擦与库仑摩擦模型,黏结-滑移摩擦模型能更准确地描述刀-屑摩擦特性。展开不同参数下的切削力研究,研究发现:切削力随着刀具前角、后角和切削速度的增大而减小,随切削刃钝圆半径和切削厚度、宽度的增大而增大,其中切削宽度、厚度及前角对切削力大小影响较大。研究结果为304不锈钢切削效率的提高和切削机制的研究提供了理论依据。 相似文献
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为解决聚晶金刚石(PCD)刀具在铝合金材料切削过程中的切屑缠绕问题,在PCD刀具的前刀面上设计了断屑槽。通过对切屑受力过程和断屑槽断屑机理的分析、切削几何关系的推导和有限元切削仿真实验,提取了5个PCD刀具断屑槽参数,即棱带宽度、倾角、反屑角、槽宽和反屑面转角。建立了PCD刀具断屑槽棱带宽度和反屑角的计算公式;改进了槽宽的计算公式;确定了倾角和反屑面转角的取值范围。结合5个断屑槽参数的求解过程,提出了PCD刀具断屑槽尺寸参数的设计方法。应用激光在PCD刀具前刀面加工出断屑槽,通过铝合金材料的切削实验对所设计的PCD刀具断屑槽的断屑效果进行验证,实验结果表明,所设计的PCD刀具断屑槽能够扩大刀具断屑的切削用量范围,具有良好的断屑效果。 相似文献