The plastic flow stability of chip materials in metal cutting process
The plastic flow stability of chip materials in metal cutting process
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金属切削过程中切屑材料的塑性流动稳定性
DOI：
10.1007/s00170-019-04353-2
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发表时间：
2019-09
期刊：
影响因子：
--
通讯作者：
Fei Shuang
中科院分区：
文献类型：
--
作者：
Wei Ma;Fei Shuang
本研究通过四种金属的高速切削实验和理论建模，研究了正交切削过程（OCP）中的切屑形成机制和相关塑性流动稳定性。根据工件材料特性和切削条件，以临界速度观察切屑形态从连续到锯齿状再到连续的转变。为了检验二维 (2D) 效应对塑性流动稳定性的影响，建立了平面应变状态下的完整理论框架来模拟 2D 正交切削过程。基于新框架，使用一组具有三个无量纲参数的控制方程来分析推导扩展切屑形成区（CFZ）中的通用不稳定准则、近似速度场和应力场。结果表明，一旦切削速度达到临界值，连续切屑的塑性流动可能会变得不稳定。与锯齿状切屑中的剪切局部变形相反，我们发现连续切屑中出现了一种新的不稳定机制，该机制由于平面应变载荷而经历均匀但严重的剪切变形。因此，提出了一个新的无量纲参数来描述连续切屑中的塑性不稳定性和锯齿状切屑中的剪切带不稳定性。从切削能量的耗散机制方面进一步研究了两种不稳定模式的差异，并且连续切屑的塑性不稳定被证明是关于刀具振动和表面加工质量的最佳不稳定模式。这些发现为通过控制塑性流动不稳定性来改进现代切削技术提供了实用的见解。
This study investigates the chip formation mechanism and relevant plastic flow stability in the orthogonal cutting process (OCP) through high-speed cutting experiments and theoretical modelling for four types of metals. The chip morphology transitions from continuous to serrated and to continuous again are observed with critical speeds depending on the work material properties and cutting conditions. To exam the influence of two-dimensional (2D) effects on plastic flow stability, a complete theoretical framework under plane strain state is established to model the 2D orthogonal cutting process. Based on the new framework, a set of governing equations with three dimensionless parameters are used to analytically derive a universal instability criterion, the approximate velocity fields, and stress fields in the expanding chip formation zone (CFZ). It is shown that the plastic flow of continuous chip may become unstable once the cutting speed reaches a critical value. In contrast to the shear localization deformation in the serrated chip, we found a new instability mechanism occurring in the continuous chip which undergoes the uniform but severe shear deformation due to the plane strain loadings. A new dimensionless parameter therefore is proposed to describe the plastic instability in continuous chip and the shear banding instability in serrated chip. The difference of two instability modes is further investigated in terms of dissipation mechanism of cutting energy, and the plastic instability of continuous chip is shown as the best instability mode regarding tool vibration and surface machining quality. These findings provide practical insights into improving modern cutting technology by controlling the plastic flow instability.
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DOI：
10.1243/pime_proc_1947_157_070_02
发表时间：
1947-06
期刊：
--
影响因子：
--
作者：
F. Bisacre;G. H. Bisacre
通讯作者：
F. Bisacre;G. H. Bisacre
DOI：
10.1007/s00170-004-2057-z
发表时间：
2005-10
期刊：
The International Journal of Advanced Manufacturing Technology
影响因子：
--
作者：
X. Luo;K. Cheng;X. Luo;X. Liu
通讯作者：
X. Luo;K. Cheng;X. Luo;X. Liu
DOI：
10.2307/3611266
发表时间：
1950
期刊：
--
影响因子：
--
作者：
R. Hill
通讯作者：
R. Hill
影响因子：
8.6
作者：
T. Burns;M. Davies
通讯作者：
T. Burns;M. Davies
DOI：
--
发表时间：
1964-03
期刊：
--
影响因子：
--
作者：
P. Oxley;M. Welsh
通讯作者：
P. Oxley;M. Welsh