摘要
以高速切削典型变形特征为研究对象,建立了锯齿状切屑的几何模型。根据高速切削绝热剪切理论,通过对剪切面相对滑移失稳瞬间的切屑块受力平衡分析建立力学模型和运动学模型,获得切屑摩擦力和剪切力及剪切速度和切屑流动速度,并确定了切削能量方程。在考虑应变、应变率、切削温度和变形硬化因素条件下按最小能量原理求变形方程,结合变形曲线的分析和切削理论确定了高速切削变形方程及影响变形的因素。分析结果表明,切屑锯齿化是塑性变形超过临界失稳条件的结果。
The geometrical model for serrated chip was set up by studying the deformation characteristic of typical chip during high speed machining. According to adiabatic shear theory under the condition of high speed machlning, fric- tion force and flow velocity on back surface of chip as well as shearing force and shear velocity on sliding plane were ob- tained by establishing mechanics and kinetic models via analyzing equilibrium forces exerted on the saw - tooth chip at the moment when the catastrophic thermoplastic instability occurred on slippage plane, and then energy equation for cutting was offered. With strain, strain ratio, cutting temperature and deformation hardening considered, deformation equation was found using the principle of minimum energy. Finally, deformation equation and factors that affect deformation during high speed cutting were ascertained combining analysis of deformation curve and cutting theory. The analysis show that serrated chip is the result of plastic deformation exceeding the condition of critic instability.
出处
《工具技术》
2012年第10期7-10,共4页
Tool Engineering
基金
国家科技重大专项基金资助项目(2010ZX04001-032)
关键词
高速切削
锯齿形切屑
集中剪切滑移
最小能量
变形方程
high speed cutting
serrated chip
catastrophic shear slide
minimum energy
deformation equations
