Characteristics of non-pressure sintering and isostatic pressure sintering

The properties of SiC ceramics with free pressure sintering, hot pressure sintering, hot isostatic pressure sintering and reactive sintering are different.For example, in terms of sintering density and flexural strength, there are more SiC ceramics in hot pressing sintering and hot isostatic pressing sintering, and less SiC in reaction sintering.On the other hand, the mechanical properties of SiC ceramics vary with the different sintering additives.Non-pressure sintering, hot pressure sintering and reactive sintering SiC ceramics have good resistance to strong acid and strong alkali, but reactive sintering SiC ceramics have poor corrosion resistance to HF and other acids.In terms of high temperature resistance, when the temperature is lower than 900℃, the strength of almost all SiC ceramics increases.When the temperature exceeds 1400℃, the flexural strength of react-sintered SiC ceramics decreases sharply.(this is due to a certain amount of free Si in the sintered body, and the bending strength drops sharply when the temperature exceeds a certain temperature.) for SiC ceramics without pressure sintering and hot isostatic pressure sintering, their high-temperature resistance is mainly affected by the types of additives.

The four sintering methods of SiC ceramics have their own advantages and disadvantages. However, with the rapid development of science and technology, it is urgent to improve the performance of SiC ceramics, continuously improve the manufacturing technology, reduce the production cost and realize the low temperature sintering of SiC ceramics.In order to reduce energy consumption, reduce production costs, promote the industrialization of SiC ceramic products.