Research On Material Removal Mechanism And Surface Topography In Ultrosonic Vibration Grinding Of SiCp/Al Composites

SiCp/Al composites have high specific strength,specific rigidity,good wear resistance and other excellent mechanical properties,so it is considered a very promising metal matrix composites.However,due to the presence of hard particles in the material to make its processing performance deteriorated,thus limiting the application of SiCp/Al composite materials.Ultrasonic vibration grinding as a highly efficient precision machining technology,provides a way to solve the SiCp/Al composite materials processing economy.Therefore,in order to achieve the precision machining of the materials and to promote the wide application of the materials,it is very important to study the removal mechanism and surface morphology of SiCp/Al composites for ultrasonic vibration grinding materials.The study of the chip formation mechanism and machined surface defects is the basis of exploring for improving the surface quality of machined surfaces.In this paper,the microscopic deformation behavior of SiCp/Al composites was studied by nanoindentation.The Young's modulus and microhardness of Al matrix and SiC particles were obtained respectively.Based on this,the critical depth of plastic removal of reinforced phase particles was obtained.The influence of ultrasonic vibration on the removal of the material was studied by scratch experiment and analyzing the contact condition between the abrasive grains and the workpiece.The experimental results show that ultrasonic vibration can reduce the scratching force,reduce the friction coefficient between diamond indenter and workpiece,and improve the scratch surface quality.The deformation of the SiCp/Al material and the interaction between the tool and the workpiece during grinding are the basis for studying the removal of the material.In this paper,In this paper a multi-phase finite element model was developed to simulate the ultrasonic vibration-assisted grinding process.The mechanism of chip formation,the crushing mechanism of SiC particles and the formation mechanism of surface defects were analyzed by simulation.Then,the effect of ultrasonic vibration on the removal of the material is analyzed by simulation.The results show that the ultrasonic vibration is beneficial to the removal of the chip,which can reduce the removal of the SiC particles and increase the crushing of the particles.Grinding surface morphology is an important index to reflect the quality of the surface.Therefore,the surface morphology of the machined surface is studied by grinding experiment.Firstly,the wavelength characteristics of the machined surface under different processing parameters were analyzed by power spectral density analysis method.And then further study the influence of processing parameters on surface roughness Ra and Sm.Finally,taking Ra and Sm as the goal of optimization,the neural network and particle optimization algorithm are used to optimize the processing parameters.