基于弹塑性理论的高速铣削表面粗糙度力学建模

Mechanical Modeling of Surface Roughness in HSM Based on Thermo-elastic-plastic Theory

基于分子—机械摩擦理论,提出了已加工表面残留高度的力学模型。并根据热—弹塑性大变形理论,对材料的流动应力方程(非线性)进行了分析,推导出了材料的应变硬化、应变率和温度与切削变形应力增量的关系,研究了不同材料(45钢和3Cr2Mo模具钢)已加工表面残留高度的实验结果,分析了材料物理性能对加工表面粗糙度的影响。

Based on the molecular-mechanical friction theory,a mechanical model was presented to investigate the influence of the material behavior on the surface roughness of machined layer.According to thermo-elastic-plastic theory for large deformation,the flow stress increment was calculated for determining the cusp height（the remnant height on machined surface）,which is induced by the strain hardening,the strain rate and the thermal loads in machining process.In addition,the relationships between the cusp height and the hardness of the material were discussed.The reasons for the observed differences in roughness between different material surfaces can be explained from the viewpoint of the molecular-mechanical friction theory.