Study On Grinding Mechanism Of Silicon Carbide Ceramics Based On Laser Modification

Silicon carbide ceramics have been widely used in many industrial fields because of its excellent material properties.Traditional grinding is the main processing method of silicon carbide ceramics.However,as silicon carbide ceramics are typical difficult-to-machine materials with high hardness and big brittleness,their machinability is poor.Moreover,it is easy to introduce subsurface damages and serious wear of the grinding wheel,which limits the further improvement of their machining accuracy and efficiency.Laser modification technology has great potential and application prospect in the surface processing of hard and brittle materials.However,the surface roughness of laser modification is high,and the surface metamorphic layer will cause the decline of the service life of the workpiece.In order to realize high-efficiency and high-precision machining of silicon carbide ceramics,laser modification and precision grinding are combined.In this paper,laser modification is introduced into the grinding process of silicon carbide ceramics.Pulse laser is used to irradiate the surface of silicon carbide ceramics in order to achieve the purpose of modification.The influences of the laser modification on grinding performance of silicon carbide ceramics were deeply investigated.The main research work is:(1)The interaction process between pulsed laser and silicon carbide ceramics was studied theoretically based on laser correlation theory,Fourier heat conduction theory and free electron theory.A heat transfer model of the interaction between pulsed laser and silicon carbide ceramics was established.The interaction mechanism between pulse laser and silicon carbide ceramics was revealed.(2)The experiment of laser modification of silicon carbide ceramics by pulse laser was carried out.The surface of silicon carbide ceramics was irradiated by pulsed laser.The influences of laser irradiation on the mechanical properties of silicon carbide ceramics were investigated based on Vickers indentation experiment.The influence of laser irradiation on the surface phase composition of silicon carbide ceramics was analyzed by X-ray diffractometer.The thickness of silicon carbide ceramic modified layer was observed by super depth of field three-dimensional microscope system.The influence of laser process parameters on the different characteristics of the modified surface of silicon carbide ceramics was investigated through single factor experiments.(3)The comparative experimental study between laser modified grinding and ordinary grinding was carried out based on the orthogonal experimental method.The influences of grinding process parameters on grinding force,surface roughness,surface morphology,subsurface damage and grinding wheel wear were investigated by relevant testing equipment.The material removal mechanism of silicon carbide ceramics was revealed.