基于单颗磨粒划切试验的SiCp/Al复合材料表面去除机理研究

Surface removal mechanism study of SiCp/Al composites based on single-point cutting test

碳化硅颗粒增强铝基(SiCp/Al)复合材料中含有不规则碳化硅颗粒使得材料内部形成大量非理想截面,为材料表面的有效去除带来困难.为了揭示材料去除机理,进行SiCp/Al复合材料单颗磨粒变切深划切的表面去除仿真分析和试验验证.研究结果表明,界面破坏对表面创成有重要影响,存在铝合金基体撕裂、界面分离,碳化硅颗粒裸露、裂纹扩展、破碎脱落、压入铝合金基体、碎片滑擦材料表面等去除过程,碳化硅颗粒中部大面积破碎脱落形成凹坑,并在刀具推挤作用下对材料进行二次切削,使铝合金基体表面形成非连续裂纹.SiCp/Al复合材料中由于铝合金基体的存在,实际划切深度小于名义切削深度.研究可以为SiCp/Al复合材料去除机理与加工研究提供一定借鉴.

SiC particle reinforced aluminum matrix(SiCp/Al)composites contain irregular silicon carbide particles,causing a large number of non ideal cross-sections in the material,which makes it difficult to remove the surface of the material effectively.Simulation analysis and experimental verification of surface removal of SiCp/Al composite with variable cutting depth were carried out,in order to reveal the mechanism of material removal.Results show that the interface failure has an important impact on surface formation and there are removal processes such as aluminum alloy matrix tearing,interface separating;silicon carbide particles exposing,crack propagation,breaking and falling off,pressing into aluminum alloy matrix,debris sliding against the material surface,etc.The large area of the silicon carbide particles crushing and falling off,causes pit defect and the material is subjected to secondary cutting under the tool push,so that the surface of the aluminum matrix forms non-continuous cracks.In SiCp/Al composites,the actual cutting depth is less than the nominal cutting depth due to the existence of aluminum alloy matrix.Research in this paper can provide some references for the study of removal mechanism and processing of SiCp/Al composites.