Effects of copper on microstructure and mechanical properties of Cf/ZrC composites fabricated by low-temperature liquid metal infiltration

Carbon fiber-reinforced zirconium carbide matrix (Cf/ZrC) composites were fabricated by a liquid metal infiltration process at 1200 °C, using low melting Zr7Cu10, ZrCu and Zr2Cu alloys as infiltrators. The effects of Cu on microstructure and mechanical properties of the composites were investigated. The results indicated that the products were composed of either single- or polycrystalline ZrC, C and Cu. With increasing Cu content in the infiltrators, the yield of ZrC decreased from 43.7 vol% to 27.9 vol%. When ZrCu was used as an infiltrator, the obtained composites exhibited a better bending strength of 98.2±3.1 MPa. What is more, the use of Zr2Cu could provide the highest fracture toughness of the composites with a moderate debonding.