Sol-gel synthesis and pressureless sintering of nanophase silicon carbide

Nanophase SiC powder was prepared by process of ammono sol-gel and carbothermal reduction using silica sol, urea and carbon black. SiC composite powder containing sintering additives was obtained with the same method by introducing aluminum nitrate and yttrium nitrate into silica sol. The resultant SiC composite powders show the potential to fabricate dense SiC ceramics with nanosized grain structures by pressureless sintering process.