SiC_(p)/Al复合材料切削加工中颗粒失效及表面缺陷形成机理仿真研究

Simulation Study on the Mechanism of Particle Failure andSurface Defect Formation in Machining of SiC_(p)/Al Composites

为揭示SiC_(p)/Al复合材料切削加工中SiC颗粒失效以及颗粒失效对材料表面微观形貌缺陷的影响,建立了单颗粒SiC_(p)/Al复合材料有限元模型,并探究了不同刀具-颗粒相对位置和切削速度下颗粒失效和表面缺陷的形成过程。通过分析应力场、颗粒失效过程和刀具-颗粒接触力变化规律发现,刀具-颗粒相对位置对SiC颗粒失效、应力场以及刀具-颗粒接触力存在显著影响,颗粒存在多种失效形式并影响加工表面形貌缺陷的形成,切削速度对颗粒失效演化和刀具-颗粒接触力的影响小。模拟结果与实验获得的加工表面形貌吻合较好。不同刀具-颗粒相对位置下应力场以及刀具-颗粒接触力的差异解释了颗粒的多种失效行为。

In order to reveal the mechanism of SiC particle failure and the effect of particle failure on the microscopic morphological defects of SiC_(p)/Al composites during cutting,a finite element model of single-particle SiC_(p)/Al composites was established,and the process of particle failure and surface defect formation under different tool-particle relative positions and cutting speeds were investigated.With the stress field analyzed,particle failure process and tool-particle contact force,it is found that the relative tool-particle position has a significant effect on SiC particle failure,stress field and tool-particle contact force,that there are various forms of particle failure which affects the formation of surface defects on machined surfaces,and that the cutting speed has little influence on the evolution of particle failure and tool-particle contact force.The simulation results show good agreement with the surface morphology obtained from experiments.The various types of particle failure are explained by differences in stress fields and tool-particle contact forces at different tool-particle relative positions.