Effects of ZrC/SiC ratios on mechanical and ablation behavior of C/C-ZrC-SiC composites prepared by carbothermal reaction of hydrothermal co-deposited oxides

C/C-ZrC-SiC composites were fabricated by carbothermal reaction of hydrothermal co-deposited oxides and resulted in homogeneous microstructure. The fracture behavior passed from pseudo-plastic to brittle fracture with the increase in ZrC/SiC molar ratios. The composites with a molar ratio of ZrC/SiC approximate to 2:1 presented outstanding ablation resistance with a mass ablation rate of 0.06 mg cm(-2) s(-1) and a linear ablation rate of 0.13 mu m s(-1). The optimal ZrC/SiC molar ratio provided a suitable balance of viscosity and flowability of the oxides scale, which not only possessed enough solid ZrO2 to endure the scouring but also had moderate liquid phase to seal the defects and limited the oxidation.