Densification of Tantalum Carbide Ceramics with 1–10 mol% LaB6

TaC ceramics were prepared by hot pressing at 1900 °C for 30 min under 30 MPa mechanical pressure. The effect of adding 1–10 mol% LaB 6 as a sintering aid on densification, the phase composition, microstructure and mechanical properties of the consolidated materials were investigated. TaC and LaB 6 reacted to form the solid solution. The grain average size decreased from 10 μm at 1 mol% LaB 6 addition to 4 μm at 10 mol% LaB 6 addition. The 5 mol% LaB 6 composition had good flexural strength of 312 MPa. Keywords Ultra high-temperature ceramic Tantalum carbide Hot pressing