Silicon nitride is an excellent high-temperature structural ceramic material that not only has excellent physical properties such as high strength, high temperature resistance, wear resistance, and low density but also can withstand the corrosion of all inorganic acids except hydrofluoric acid and hydrochloric acid, exhibiting excellent chemical stability. Dense ceramic bearings have been increasingly used in precision transmission systems such as electroplating equipment, high-speed machine tools, medical devices, chemical equipment, cryogenic engineering, and wind power generation. The product quality meets the requirements of high-precision hot isostatic pressing (HIP) silicon nitride ceramic specifications.