Densification and Microstructural Evolutions during Reaction Sintering of SiC-Si-C Powder Compacts

Abstract EN

Porous SiC-Si-C ceramics were produced by reaction sintering (RS) of silicon carbide, silicon, and carbon powder compacts in the temperature range of 1400–1600°C.

The effects of chemical composition of the starting powder, initial SiC particle size, and reaction sintering temperature and duration on the densification and microstructure of ceramic materials were studied.

The results showed that increasing the amount of Si and/or C powders in the starting powder mixture had a detrimental influence on the densification of ceramic material as a result of higher amount of remained silicon and carbon phases in the ceramic specimen.

Increasing the RS temperature also degraded densification due to the melting of Si and coming out of it from compact during heating.

Nevertheless, densification was improved by increasing the RS duration.

Using nanometric SiC particles in the starting powder mixture improved the densification compared to that of micrometric ones especially at longer RS processing duration.