Experimental Study On Surface Roughness Of Cutting SiCp/Al Composites With High Volume Fraction

SiCp/Al composites have been widely used in aerospace,automotive,electronics,military and precision instruments because of their good physical properti es,simple molding methods and low manufacturing and processing costs.However,due to the characteristic of SiCp/Al composite materials internal uneven characteristic,cause the SiCp/Al composite materials in the process of machining,easy to cause processing surface defects,the production of the processing surface roughness such as a series of problems,especially with the increase of Si C particle volume percentage,its machining,the surface roughness is more difficult to control.Therefore,this article in view of the high volume of SiCp/Al composite materials processing problems existing in the process of the experiment and research,by cutting dosage and cutting tool geometry as optimization object,the surface roughness as the main optimization goal,power coefficient for the secondary optimization goal,to optimize cutting parameters and to explore the influence of various parameters on surface roughness,master get smaller surface roughness parameter selection method.Furthermore,a multi-objective optimization model was established by taking the power coefficient and surface roughness as targets,and the cutting amount and tool geometry as parameters.It provides a reference for the selection range of cutting parameters of SiCp/Al composites in the actual cutting process.The main contents and conclusions are as follows:1.The surface defects of SiCp/Al composites in the process of machining were studied in depth.The formation mechanism of the surface defects,the types of surface defects and the factors affecting the surface roughness of the composites were investigated.It is found that the main factors affecting the surface roughness of SiCp/Al composites are the preparation technology,the amount of cutting,the tool material and the tool shape.2.The surface roughness of turning high volume fraction SiCp/Al composites was studied by Taguchi method.According to variance analysis,it is found that the feed rate and nose radius are the significant factors affecting the surface roughness,while the depth of cut and cutting speed are the non-significant factors.A prediction model of quadratic regression equation for surface roughness is established,and the accuracy of the model was verified by experiments.3.The surface roughness and power coefficient of high volume fraction SiCp/Al composites were optimized by multi-objective method.It is found that the order of influence of cutting parameters on surface roughness is as follows: feed rate,nose radius,approach angle,depth of cut and cutting speed.The order of influence on power coefficient is as follows: depth of cut,feed rate,cutting speed,approach angle and nose radius.The optimal parameter combination was obtained as follows: nose radius is 0.8mm,depth of cut is 0.25 mm,feed rate is 0.12mm/r,cutting speed is299.87m/min,approach angle is 62.5°.The results were verified by experiments.