SiC_(p)/Al复合材料微弧氧化膜层单磨粒去除仿真研究

Study of Simulation of Single Abrasive Particle Removal in Micro-arc Oxidation Film of SiC_(p)/Al Composites

研磨是SiC_(p)/Al复合材料精密加工的关键工序,针对两相力学性能相差大、研磨表面缺陷多且难度大的问题,提出通过微弧氧化形成氧化膜后再进行研磨的复合加工方法。为验证其去除效果,通过ABAQUS有限元软件进行单磨粒去除仿真,基于Johnson-Holmquist ceramic硬脆材料本构方程建立模型,研究相同参数下切削氧化膜不同位置时的材料去除特性及膜层特征对材料去除的影响,分析在不同切削深度下的去除特性。结果表明,材料在致密层和疏松层的去除均十分平稳,膜层越致密,切削力越大;切削到碳化硅颗粒时存在应力集中,但去除效果较好无明显的台阶缺陷。实验证明,表面微弧氧化后进行研磨精密加工方法是可行的。

Grinding is a key process in the precision machining of SiC_(p)/Al composites.It is aimed at the problems that the mechanical properties of the two phases are greatly different, the surface defects are many, and the grinding is difficult.A composite machining method is proposed to form an oxide film by micro-arc oxidation and then grind it.A single abrasive grain removal simulation is carried out by ABAQUS finite element software to verify the removal effect.Based on the constitutive equation of Johnson-Holmquist ceramic, a model is established to study the material removal characteristics of different positions of the oxide film under the same machining parameters, the influence of film characteristics on material removal, and the removal characteristics at different cutting depths.The results show that the removal of the dense layer and the loose layer is very smooth, and the denser the film layer, the greater the stress.There is stress concentration when cutting silicon carbide particles, but the removal result is good without obvious step defects.Thus, the feasibility of the precision machining method of grinding after surface micro-arc oxidation is verified.