Effect of Tantalum Carbide Addition on the Properties of SiC-B-C Ceramics

Abstract

The densification of SiC-B-C composites doped with TiC, ZrC, HfC, VC, NbC, TaC or WC were investigated by pressureless sintering. Densities over 90% TD (theoretical density) were achieved by addition of TaC by sintering at a relatively higher temperature. TaC particles suppressed the grain boundary movement. Addition of 10mol% TaC doubled the toughness of composites under the same sintering conditions. Exposed TaC particles were oxidized severely at 1500°C in air, and formed Ta₂O₅ polymorphisms.