Effects of Ti/Al addition on the microstructures and ablation properties of Cf/C-MoSi2-SiC composites

Porous carbon/carbon composites were infiltrated by Mo-Si-Ti/Al mixed powder to develop a Cf/MoSi2-SiC-C based composites below 1600 °C in this research. Effects of Ti/Al addition on the microstructures and ablation properties of infiltrated samples were investigated and compared together with Si-Mo infiltrated samples. The infiltrated samples are composed of SiC, MoSi2 and ceramic phases containing Ti or Al. Ceramic phases containing Al distribute close to carbon fiber bundles while ceramic phases containing Ti distribute far away from carbon fiber bundles. Samples infiltrated by Mo-Si-Ti showed excellent ablation properties. The linear ablation rate and mass ablation rate after ablated for 300 s under an oxyacetylene torch system are 0.002 mm/s and 0.01 mg/s, respectively. Addition of Al has not improved ablation resistance significantly in this research.