Research On Al₂O₃ Ceramic Grinding Process Based On Laser Thermal Assistance

As a typical hard and brittle material,alumina engineering ceramics has the advantages of high strength,high wear resistance,high hardness,low thermal conductivity and chemical stability.It can maintain stable performance under harsh working conditions and can maintain very good High mechanical strength and excellent resistance to wear.Engineering ceramic materials have been gradually applied in chemical engineering,aerospace,petroleum exploration,metallurgy,machinery,electronics,national defense and cutting-edge science and technology fields,and have become more and more important.They have become an important pillar of modern engineering structural materials.One of them has a very broad application prospect.Laser-assisted processing(LAM)is considered to be a promising technology for improving the removal rate of ceramic materials.Laser-assisted heating uses the high energy density of the laser to heat the material to instantly increase the temperature of the material,which can change the brittleness of the ceramic material.The removal also reduces the ceramic yield strength value below the fracture strength,which reduces the processing difficulty of the ceramic material.The main research contents of this paper are as follows:(1)Analysis of brittle material removal mechanism in the processing,the brittle material plastic removal is analyzed in theory,through the grinding process of indentation fracture model and geometric model of brittle-ductile transition of critical depth and critical feed conditions were studied according to the geometric model of grinding and scratch grinding crack extension system analysis the influence law of process parameters on the material removal rate.(2)According to the heat conduction theory,the mathematical model of heat conduction during laser heating of alumina ceramics was established,and the finite element simulation was carried out according to the established theoretical model and boundary conditions.The temperature of the laser heated alumina ceramic surface was measured by thermocouple temperature measurement method,and the accuracy of the heat conduction finite element simulation model was optimized by temperature measurement.(3)The absorption coefficient of the heating of the alumina ceramic by the finite element simulation and the temperature measurement experiment of the laser-heated alumina ceramic was obtained.The obtained absorption coefficient and the optimized simulation model were used to study the different laser parameters for heating the alumina.The temperature field distribution of the ceramic surface and the temperature gradient in the longitudinal depth direction predict the selection range of the laser process parameters in the laser-assisted heating grinding process.(4)A laser-assisted heating grinding experimental platform was built to optimize the experimental parameters predicted by simulation,and orthogonal experiments of laser-assisted heating grinding and conventional grinding were carried out using optimized process parameters.Comparing the experimental results of laser-assisted heating grinding and conventional grinding,the effects of the two processes on the surface quality and the wear of the grinding wheel were analyzed.According to the orthogonal experimental results,the importance of process parameters on surface roughness was analyzed.The influence of process parameters on surface roughness during laser-assisted heating grinding process was analyzed.