Generally, the content of SiC in the green or black industrial silicon carbide first-class product is 98% or more, and the impurities are mainly unreacted Si, SiO2, C, and trace amounts of Fe, Al, Ca, Mg, and the like. SiC has a very high degree of refractoriness, has no melting point in the atmosphere, and begins to sublimate above 2,300 degrees, and decomposes into silicon vapor and graphite to more than 2,600 degrees. Creep does not occur due to the liquid phase at high temperatures. Before 1500 °C, the mechanical strength of SiC increased slightly with temperature, so SiC is an ideal high-temperature structural material.

SiC has a high thermal conductivity of more than 10 times that of a typical high-aluminum refractory. At the same time, the coefficient of thermal expansion of SiC is small. Due to the high temperature stability, high mechanical strength and thermal conductivity of SiC material, and small thermal expansion coefficient, it has excellent high temperature strength and thermal shock resistance. It is used to make ceramic kiln firing kiln with almost no deformation. , cracking and chipping phenomenon; using its high strength and high thermal conductivity, the crucible or the slab can be made very thin, reduce the loading ratio of the kiln furniture and the porcelain, and can realize the rapid firing of the ceramic product. SiC is very stable in reducing atmosphere and neutral atmosphere, and there is no obvious decomposition reaction until 2200 °C; however, under oxidizing atmosphere, SiC starts to oxidize slightly at 900-1100 degrees, and a very thin SiO2 protective film is formed on the surface. When the temperature continues to rise, the SiO2 film is transformed into denser cristobalite, which inhibits oxidation and slows down the oxidation rate. This phenomenon is also called "pure oxidation". Therefore, whether a SiC surface can form a dense protective film is a basic condition for its antioxidant ability. At 1700 degrees, SiO2 melts, so the ultimate use temperature of SiC in an oxidizing atmosphere should be less than 1700 degrees.