Preparation of 3D Cf/ZrC–SiC composites by joint processes of PIP and RMI

Abstract

Three-dimensional carbon fiber zirconium carbide–silicon carbide composite (3D Cf/ZrC–SiC) was prepared by precursor infiltration and pyrolysis (PIP) with reactive melt infiltration (RMI) process. The 3D Cf/C–SiC substrate with open porosity of 20% and density of 1.35g/cm3 was designed to be infiltrated by Zr0.912Si0.088 intermetallic compound. Thermodynamics calculations revealed that C could react with liquid Zr0.912Si0.088 to form ZrC at 1600°C. Composites were prepared by heating the two materials to 1600°C for 1h in vacuum. The micro-structural, mechanical and ablative properties of the 3D Cf/ZrC–SiC composite were studied. ZrC and SiC were identified to be the main constituents. The flexural strength of the composite was 101.5±8.16MPa and the elastic modulus was 35.18±9.58GPa. The mass loss rate and linear recession rate of the 3D Cf/ZrC–SiC composite during oxyacetylene torch test were 0.013g/s and 0.022mm/s, respectively. The formation of ZrO2 melt on the surface of the composite contributed mainly to the excellent ablative property.