基于分子动力学的磨粒微切削单晶铁数值分析

Numerical analysis of single crystal Fe with abrasive grain micro-cutting based on molecular dynamics

为探讨磨粒流加工过程中工件材料去除机制,采用分子动力学方法模拟碳化硅颗粒微切削单晶铁的加工过程,研究磨粒微切削单晶铁过程中影响切削力变化的微观作用机制及切削力产生持续波动的原因,揭示磨粒微切削作用下工件材料发生物理变化的内在原因及磨粒对工件的做功规律。通过原子位移分析可知,磨粒微切削过程中材料的塑性变形主要是由晶格内滑移面上产生滑移区域从而形成位错,原子在切削力作用下沿位错线发生运动所导致,同时,探讨了原子的堆积现象及切屑形成机制。通过多面体模板匹配方法对微切削过程中工件原子排布情况进行了分析,探讨了工件材料内晶格结构的变化情况。本文研究可为磨粒流精密加工单晶铁工件材料提供理论基础和技术支持。

In order to explore the mechanism of workpiece material removal during abrasive flow machining,the molecular dynamics method was used to simulate the machining process that SiC particles micro-cut single crystal Fe. The microscopic mechanism of action that affects the cutting force variation and the reasons for the continuous fluctuation of cutting force in the process are studied. The internal reasons of physical change of workpiece material and the working law of abrasive grains on workpiece are revealed under the micro-cutting process. Through the analysis of atomic displacement,it can be seen that the plastic deformation of the material in the micro-cutting process is mainly caused by the slip region generated in the sliding surface of the crystal lattice to form dislocations,and the atoms move along dislocation lines. At the same time,the accumulation of atoms and the mechanism of chip formation are discussed. The polyhedron template matching method was used to analyze the arrangement of workpiece atoms in the micro-cutting process,and the variation of the lattice structure in the workpiece material was discussed. The research can provide theoretical basis and technical support for processing single crystal Fe with abrasive flow machining.