C/C-ZrC composite prepared by chemical vapor infiltration combined with alloyed reactive melt infiltration

摘要

A high performance and low cost C/C-ZrC composite was prepared by chemical vapor infiltration combined with zirconium-silicon (Zr: 91.2 at.%; Si: 8.8 at.%) alloyed reactive melt infiltration. The density of the as-received composite is 2.46 g/cm~3 and the open porosity is 5%. Due to the reaction between the pyrolytic carbon and Zr-Si alloy in the composite, ZrC and Zr_2Si phases were formed, the formation and distribution of which were investigated by thermodynamics and phase diagram. The as-received C/C-ZrC composite, with the flexural strength of 239.5 MPa, displayed a pseudo-ductile fracture behavior. Ablation properties of the C/C-ZrC composite were tested by a pulse laser. The linear ablation rate was 0.028 mm/s. A ZrO_2 barrier layer was formed on the ablation surface and the composite presented excellent ablation resistance.