Microstructure and properties of W-ZrC composites prepared by the displacive compensation of porosity (DCP) method

摘要

Tungsten-zirconium carbide composites were fabricated at different temperatures by the displacive compensation of porosity (DCP) method, the microstructure, mechanical properties, and ablation resistance were investigated. It was found that no WC phase was left in the composites prepared at 1400°C, and a few residual W_2C particles were surrounded in W product. Microstructure analyses revealed that zirconium atoms diffused into tungsten carbide to form ZrC and W_2Zr besides carbon diffused into the Zr2Cu melt. Composites fabricated at 1400 °C had a flexural strength of 356.7 ± 15.2 MPa, an elastic modulus of 193.7 ± 9.8 GPa, a fracture toughness of 7.0 ± 0.7 MPa m~(1/2), and a hardness of 13.6 ± 0.7 GPa. After ablated by an oxyacetylene flame for 30 s, the higher temperature prepared composites had a better ablation resistance, the linear ablation rate was 0.0033 ± 0.0004 mm/s, and the mass ablation rate was 0.0012 ± 0.0001 g/s.