Possibility of using boric acid and glutinous rice flour as additive for producing silicon carbide ceramic via pressureless solid-state sintering

Abstract

This research aimed to investigate the possibility of using the mixture of boric acid and glutinous rice flour as a cost-efficient alternative additive for producing silicon carbide (SiC) ceramic sintered at 1800℃ via pressureless solid-state sintering. The results indicated that the addition of boric acid- glutinous rice flour mixture (10 wt%) in an appropriate ratio (0.5 by molar ratio) into the SiC mixture (90 wt%) enhanced the densification and flexural strength of sintered SiC samples. However, increasing boric acid/glutinous rice flour ratio reduces density and flexural strength. The 5.45 wt% carbon content was sufficient to remove the oxide layer of the SiC surface and improve the properties of SiC ceramic. In summary, the boric acid-glutinous rice flour mixture has a high potential to be used as an additive for producing dense and porous SiC ceramics via pressureless solid-state sintering.