Nano-TaC powder synthesized using modified spark plasma sintering apparatus and its densification

Using a modified spark plasma sintering apparatus, nano-tantalum carbide powder was synthesized at 1450 °C by the carbothermal reduction of Ta2O5. The synthesized TaC powder had ultra-fine particle size of 62 nm and a low oxygen content of about 0.5 wt%. The metal basis purity of the synthesized powder was 99.94%. The particle growth during synthesis was effectively suppressed by using the modified spark plasma sintering process due to the low synthesis temperature and fast heating/cooling rate. Dense monolithic TaC ceramics were obtained by sintering the synthesized powder without sintering additives at 2200 °C for 30 min under 80 MPa pressure. The average grain size of the dense TaC ceramics was 4 μm.