technology of sintered silicon carbide

silicon carbide ceramic are more and more widely used because of their excellent high temperature strength, wear resistance, corrosion resistance and thermal shock resistance. SiC ceramics play an increasingly important role in the field of materials. Therefore, it is urgent to carry out further research on SiC materials in order to reduce production costs, simplify production processes and promote the development of SiC ceramic products while continuously improving their excellent properties.

sintered silicon carbide is considered as the most promising sintering method for SiC sintering. silicon carbide ceramic with large size and complex shape can be prepared by atmospheric sintering process. GE Corporation of the United States has adopted the following measures: β – Adding boron and carbon into SiC, sintering at above 2000 ℃ in inert atmosphere, and obtaining sintered silicon carbide with density higher than 98% at 2020 ℃. With Y2O3 and Al2O3 as sintering aids and YAG (Y3Al5O12) with low melting point as basic component, Shanghai Institute of Silicate, Chinese Academy of Sciences fired silicon carbide ceramic with bending strength and fracture toughness of 707 and 10.7 respectively at 1850 ℃. Liu Baoying of Shandong Silicate Research and Design Institute added appropriate amount of Al2O3 and Y2O3 as sintering additives, and made fine SiC composite ceramic materials with relative density of 97% at 1780 ℃ by using the grouting molding process, which can meet the needs of industrial production of mechanical seals and wear-resistant ceramics. But so far, the research about sintered silicon carbide is not very thorough, which needs to be further deepened.