Study on the removal mechanism of 4H-SiC materials based on single grain grinding and optimization of process parameters

Single crystal silicon carbide is a new third-generation semiconductor material suitable for high temperature, high power, high voltage, high frequency, and radiation resistance, and it is widely used in the field of power electronics. However, due to its properties such as high brittleness, high hardness, and low fracture toughness, it seriously affects the processing quality and manufacturing cost of the products. In this paper, the formation and propagation of cracks and plastic removal conditions in the grinding process of single crystal silicon carbide materials were studied through single diamond grain grinding simulation and experiments. The influence of processing parameters on the maximum chipping width was analyzed using grinding wheel experiments. It was found that the grinding process of single crystal silicon carbide can be divided into four stages: plastic removal, crack initiation, crack extension, and brittle fracture. The formation of cracks during the grinding process can be effectively reduced by controlling the machining parameters. The experiments of grinding single crystal silicon carbide wafers with grinding wheels show that the maximum chipping width increases with the increase of feed rate and grinding depth, decreases initially, and then increases with the increase of grinding wheel speed; the optimal machining process parameters are n = 30,000 rpm, vw = 1 mm/s, ap = 200 mu m within the given process parameter intervals.