Hot Pressing of Tantalum Carbide With and Without Sintering Additives

Densification of tantalum carbide (TaC) was studied by hot pressing at temperatures ranging from 1900° to 2400°C with and without sintering additives. Without sintering additives, the relative density increased from 75% at 1900°C to 96% at 2400°C. A microstructural examination showed no observable grain growth up to 2300°C. Densification was enhanced with carbon (C) and/or B 4 C additions. TaC with a 0.78 wt% C addition achieved a relative density of 97% at 2300°C. Additions of 0.36 wt% B 4 C or 0.43 wt% B 4 C and 0.13 wt% C increased the relative density to 98% at 2200°C, accompanied by rapid grain growth at 2100°C and higher temperatures.