Properties of silicon carbide ceramics from gelcasting and pressureless sintering

•Dextrin was first used for the gelcasting of SiC.•Reliable gelcasting process was developed.•SiC ceramics with high reliability was prepared.

In this paper, dense silicon carbide ceramics were prepared by aqueous gelcasting and pressureless sintering using dextrin as the carbon source. The influence of carbon content and solid content on the microstructure and mechanical properties of green and as sintered SiC samples was studied. It was shown that the carbon content should be 1 wt% or higher for the fully densification of silicon carbide ceramics. The influence of solid content on the green density and the mechanical properties of SiC ceramics was studied. The optimal solid content with 1 wt% carbon as sintering additives is around 52 vol%. Results showed that dextrin is an effective carbon source for developing SiC ceramics by aqueous gelcasting and pressureless sintering method.

Graphical abstractDense silicon carbide ceramics with high performance were developed by aqueous gelcasting and pressureless sintering using dextrin as the carbon source.Figure optionsDownload full-size imageDownload as PowerPoint slide