Silicon carbide ceramics have excellent properties such as high temperature strength, high temperature oxidation resistance, good wear resistance, good thermal stability, small thermal expansion coefficient, high thermal conductivity, high hardness, thermal shock resistance, and chemical corrosion resistance. Has been widely used in automotive, mechanization, environmental protection, aerospace technology, information electronics, energy and other fields
The sintering methods of silicon carbide ceramics are divided into: pressureless sintering SiC ceramics, hot isostatic pressing sintering SiC ceramics and reaction sintering SiC ceramics. Different sintering methods have different ceramic properties.
In terms of sintering density and flexural strength, SiC ceramics have relatively more hot pressing sintering and hot isostatic pressing sintering, and reaction sintering SiC is relatively low. On the other hand, the mechanical properties of SiC ceramics vary with sintering aids. Pressureless sintering, hot pressing sintering and reaction sintering of SiC ceramics have good acid and alkali resistance, but reaction sintered SiC ceramics have poor resistance to super acid corrosion such as HF. When the temperature is lower than 900 °C, the flexural strength of almost all SiC ceramics is greatly improved than that of high-temperature sintered ceramics, and the flexural strength of reaction sintered SiC ceramics decreases sharply when it exceeds 1400 °C. For pressureless sintered and hot isostatic pressing sintered SiC ceramics, the high temperature properties are mainly affected by the types of additives.
Keyword: ceramic balls