Investigation On Inner Surface Quality And Hole Edge Defects In Ultrasonic Vibration Drilling Of Aluminum Silicon Carbide With High Volume Fraction

Aluminum-based silicon carbide(Si C_p/Al)is composite material with promising applications in aerospace,electronics and optical engineering,etc.When the volume fraction of silicon carbide is greater than 50%,it is often referred to as high-volume fraction Si C_p/Al.High volume fraction Si C_p/Al has higher brittleness and hardness,which often leads to edge and surface defects,such as chipping,brittle fracture,and sub-surface damage during machining,so precision machining of high volume fraction Si C_p/Al has become a hot research topic in the field of cutting difficult-to-machine materials.In response to the above problems,this project conducts an in-depth study on the defect formation,damage characteristics,and quality control of ultrasonic vibration drilling of high volume fraction Si C_p/Al.The main research contents of this paper are as follows:(1)The microscopic removal characteristics of plastic brittleness of high volume fraction Si C_p/Al were revealed by the analysis of the scratching force and scratch morphology based on the single-grain diamond variable tangential depth scratching test;the influence law of ultrasonic vibration on the scratch quality was explored by the constant tangential depth scratching test.(2)Establishment of a simulation method for cutting high volume fraction Si C_p/Al.ABAQUS simulation software was used to model the Al matrix and Si C particles of the high-volume fraction Si C_p/Al material separately and finally combined together using a binding connection to simulate the different removal characteristics when the tool cuts the material.The accuracy of the simulation analysis was verified by comparing the simulated surface characteristics with the experimental results under the corresponding parameters.(3)The hole wall morphology of ultrasonic vibration drilling of PCD twist drill was investigated by a combination of simulation and experiment,the surface morphology characteristics of the tool when cutting Si C particles from different thicknesses were analyzed,the process of forming the surface morphology of the workpiece was simulated,the influence of the stress on the particle and the size of the particle on the surface morphology of the machining was revealed,and the influence of the machining parameters on the surface quality of the bore was studied.(4)A combined simulation and experimental approach was used to study the hole defects in ultrasonic vibration drilling of PCD twist drills,the formation process of hole exit defects was simulated,the types of defects produced were statistically analyzed,the influence of feed per tooth on exit defect types was revealed,on this basis,the influence law of machining parameters on hole deficiency size was analyzed.(5)Experimental studies of ultrasonic vibration drilling(UVD)and ultrasonic vibration pecking drilling(UVPD)of sintered nesting drills with high volume fraction Si C_p/Al were carried out.The effects of process parameters on the average axial force and the peak-peak value of axial force were analyzed to reveal the surface characteristics of the bore under different processes;Based on the experimental results,a regression equation for the surface roughness of the bore was established,optimized machining parameters were obtained,and experimental verification was carried out;The regression analysis of the maximum deficit size of the hole was carried out to study the basic law of the influence of the machining parameters.