Research On Formation Mechanism And Control Method Of Surface Defects In Cutting Of SiCp/Al Composites

SiCp/Al composites have been widely used in the field of aerospace,military,automobile and electronic etc because of its perfect advantage.But the machinability of SiCp/Al composites is greatly reduced as the presence of SiC particles,and poor machined surface quality is obtained in the cutting.So in recent years,SiCp/Al composites cutting technology has received great attention.This paper studied the formation mechanism of surface defects in cutting by finite element simulation,then took surface roughness as evaluation criteria.We studied surface roughness by controlling cutting parameters,so that we achieved the purpose of surface defect control method research.Firstly,this paper established the finite element simulation model that defined the characteristic of SiC particles and Al matrix respectively,and the microscopic finite element model of the SiCp/Al composites was carried out by ABAQUS finite element analysis software to analyze the distribution of surface stress of SiCp/Al composite and stimulate the formation process of chip and surface defects.Secondly,The cutting experiments of 4 factors and 4 levels were conducted based on orthogonal test and surface roughness was tested on the composites cut by an centre lathe.The value of surface roughness at each level of the cutting parameters was achieved,and the practical basis was provided for the following research and analysis.Thirdly,the surface roughness prediction model was built to establish the surface roughness,the parameters of the prediction model were calculated by cutting the test data,and the prediction model of surface roughness was established.Finally,the influence of parameters on the surface roughness was analyzed based on the Taguchi method,and the sensitivity of the surface roughness to the parameters was analyzed to optimize the cutting parameters in order to obtain the optimal parameter combination.The results showed that the theoretical analysis was consistent with the data analysis of the cutting experiment,which proved that the theoretical analysis of the surface roughness was correct.Because the deviation between the finite element analysis of the surface roughness values and cutting experimental results small and stable,the establishment of the finite element model was correct.Through the comparative analysis,the multiple regression equation prediction models were closer to the experimental value than the exponential equation prediction model,so the multiple regression equation was more favorable for the prediction of surface roughness.The effects of the parameters on the surface roughness values at various levels were analyzed by using the Taguchi method,and obtained the optimal parameter.