Elevated temperature ablation resistance of HfC particle-reinforced tungsten composites

Abstract

The effects of adding HfC particles on the ablation resistance of HfC-W composites were investigated. An oxyacetylene torch was used to ablate the samples at high temperature. Ablation resistance improved with an increasing volume fraction of HfC particles, with a value of 15.7 x 10(-3) g/cm(2).s at 30 vol.%. The mass ablation rates of the composites were much lower than those of monolithic tungsten. The improvement in ablation resistance was attributed to thermochemical oxidation of the W and HfC particles, forming an HfO2 layer on the surface. The outstanding elevated temperature ablation resistance of HfC-W was attributed to the low thermal conductivity, high oxidation resistance, and high melting point of the HfC reinforcement. (C) 2013 Elsevier Ltd. All rights reserved.