1, high hardness, good wear resistance, small thermal conductivity, good chemical stability, high corrosion resistance, high fire resistance  can withstand temperatures up to 2000 ℃. 3, good chemical stability  high temperature resistant to acid corrosion 4, strength, wear resistance, good chemical stability, good biocompatibility, high density 5, is a kind of high temperature resistance, wear resistance, corrosion resistance of inorganic non-metallic materials, melting point as high as degrees Celsius, is fireproof performance is one of the best materials in the nature