Study On Grinding Mechanism And Surface Quality Processing Technology Of SiCp/Al Composites

SiCp/Al composites not only have many excellent material properties,such as higher specific strength and lower thermal expansion coefficient,but also can meet different needs by changing the volume fraction of SiC particles.This material has been widely used in many fields.However,the processing of composite materials is facing a series of difficult problems.Among them,the grinding mechanism of composite materials and reasonable processing methods are the key technologies and problems.This paper has conducted in-depth research around the two aspects.Firstly,this subject established a theoretical model of the grinding force for grinding SiCp/Al composites,followed by doing finite element simulation using ABAQUS.Finally,this paper combined the single-factor experiments and orthogonal experiments to study the grinding process of SiCp/Al composites and the grinding force and the surface quality of the grinding were analyzed in detail.On the basis of this,the grinding process parameters were optimized and the grinding status was monitored online by acoustic emission signals.It was divided into the following three parts:(1)Study on the grinding force of SiCp/Al composites.A theoretical model of the grinding force of SiCp/Al composites was established from the three component forces of chip formation force,friction force,and fracture and breaking force of SiC(reinforced)particles.Combined with the five-level single-factor experiments,the finite element simulation of the grinding force of single-grind grinding of SiCp/Al composites was analyzed in detail about the influence of processing conditions on the grinding force.(2)Research on the high surface quality processing technology of SiCp/Al composites.From the aspects of surface characteristics and surface roughness,the grinding performance of two different grinding wheels was compared when grinding SiCp/Al composites.By analyzing the results of the above grinding experiments,this paper gave the changes in surface roughness and surface characteristics with the grinding depth,the linear speed of the grinding wheel and the speed of the workpiece.At the same time,the grinding process conditions with better surface quality of 20%and 55%SiCp/Al composites grinded by two grinding wheels could be obtained,and the main defects of the processed surface could be summarized by analyzing the surface characteristics.(3)Research on acoustic emission monitoring during grinding of SiCp/Al composites.The effects of grinding depth ap,wheel linear velocity vs.workpiece velocity vw on the effective value and spectrum of the acoustic emission signal were obtained through single-factor experiments.The analysis of the frequency spectrum determined the frequency bands corresponding to the three acoustic emission sources:brittle removal,plastic removal of SiC,and plastic removal of Al matrix in SiCp/Al composites.