Elevated temperature ablation resistance and thermophysical properties of tungsten matrix composites reinforced with ZrC particles

In order to improve the elevated temperature ablation resistance of the copper infiltrated tungsten materials (Cu/W) which are used as the rudders of the rocket motors at present, a new kind of tungsten matrix composites reinforced by 30 vol% zirconium carbide particles (ZrC_p/W) was developed, and the elevated temperature ablation resistance and thermophysical properties of the new materials were investigated. The values of the mass ablation rate and linear ablation rate of ZrC_p/W were much lower than that of Cu/W, which indicated that the addition of ZrC particles in tungsten matrix remarkably increased the ablation resistance. Thermal thermochemical oxidation of tungsten and ZrC particles was the main ablation mechanism of ZrC_p/W. A self-made dynamic responding multi-wavelength pyrometer was employed to measure the ablated surface temperatures and a thermal couple was employed to measure the back surface temperatures. The important temperature curves of the ablated surface and back surface of the specimens were successfully detected online, which indicated that ZrC_p/W has good thermal shock resistance. The present of ZrC particles in tungsten matrix remarkably decreased the thermal conductivity and thermal diffusivity of the ZrC_p/W composites, which is very useful for increasing the elevated temperature ablation resistance of the composites. The excellent elevated temperature ablation resistance of ZrC_p/W is attributed to the lower thermal conductivity, lower thermal diffusivity, oxidation resistance and high melting points. The good properties of ZrC_p/W makes it be suitable for the rudders for rocket motors instead of Cu/W.