摘要
锯齿状切屑是钛合金高速切削加工中的显著特征,会引起切削力的高频周期性波动,进而影响工件已加工表面质量。深入了解锯齿状切屑的形成过程及演变机理有助于优化高速切削加工工艺。本文通过确立材料本构模型、刀—屑分离准则和摩擦模型,创建钛合金高速切削热力耦合有限元模型,并对单节锯齿状切屑形态演变过程中的等效塑性应变、温度场和应力场分布规律进行实时动态分析。在此基础上,提出钛合金高速切削锯齿状切屑的四阶段演变模型。研究结果表明:锯齿状切屑的形成过程可以分为绝热剪切带的启动阶段、萌生阶段、快速发展阶段和沿着绝热剪切带的整体集中剪切滑移阶段,绝热剪切带内的材料发生热塑失稳是锯齿状切屑形成的诱因,试验结果可很好地揭示钛合金高速切削过程中锯齿状切屑的形成过程和演变机理。
Serrated chips are the most distinct feature in high-speed machining of titanium alloys,which induces high-frequency fluctuations in cutting forces and consequently affects the surface quality of workpieces.Thoroughly understanding the formation process and evolution mechanism of serrated chips is conducive to optimizing high-speed machining processes.In this study,a thermo-mechanical coupled finite element model for high-speed machining of titanium alloys is established by developing constitutive models,tool-chip separation criteria,and friction models.Real-time dynamic analyses of equivalent plastic strain,temperature field,and stress field distributions during the formation process of a single serrated chip are performed.Based on the simulation results,a four-stage evolution model is proposed for serrated chip formation in high-speed machining of titanium alloys.The results reveal that the formation process of serrated chips can be divided into four stages:inception of adiabatic shear band,nucleation,rapid propagation,and concentrated shear sliding.Thermoplastic instability within the adiabatic shear band is the inducement for serrated chip formation.The proposed model can well elucidate the formation process and evolution mechanism of serrated chips during high-speed machining of titanium alloys.
作者
崔方圆
李鹏阳
李言
陈小龙
Cui Fangyuan;Li Pengyang;Li Yan;Chen Xiaolong(School of Mechanical Engineering,Henan Institute of Technology,Xinxiang,Henan 453003,China;不详)
出处
《工具技术》
北大核心
2025年第8期78-84,共7页
Tool Engineering
基金
国家自然科学基金(52075439)
博士科研启动基金项目(KQ2009)。
关键词
高速切削
钛合金
有限元模拟
锯齿状切屑
演变机理
high speed cutting
titanium alloy
finite element simulation
serrated chip
formation mechanism
作者简介
第一作者/通信作者:崔方圆,博士,讲师,河南工学院机械工程学院,453003河南省新乡市。
