Preparation and Ablation Properties of W/TaC Cermet via in-situ Reaction Sintering Process

Abstract

An attractive way to prepare W/TaC based cermet at a relatively low temperature was proposed and confirmed experimentally. The thermodynamics calculations indicated that the reaction between WC and Ta₂O₅ was feasible at as low a temperature as 1 400 °C. The experimental results showed that W/TaC cermet could be fabricated by in-situ reaction sintering process at 1400 °C for 2 h in vacuum. The open porosity and bulk density of the W/TaC cermet were 15.3% and 13.4 g/cm³. Further, the microstructural features revealed that W, TaC, and Ta₂WO₈ were identified to be the main constituents of the W/TaC cermet. The mass lose rate and linear recession rate of the W/TaC cermet during an oxyacetylene torch test were 0.0048 g/s and 0.0233 mm/s, respectively. The high porosity, the presence of Ta₂WO₈ phases within W/TaC and evaporation of WO₃ on the surface of the composite contributed to the decrease of ablative property when comparing with pure W.

Keywords

sintering / composites / carbides / cermet

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