Fabrication of Cf/ZrC-SiC composites using Zr-8.8Si alloy by melt infiltration

Cf/ZrC-SiC composites were fabricated by melt infiltration at 1800 °C using Zr-8.8Si alloy and carbon felt preforms. Microstructural analysis showed the formation of both ZrC and SiC phases in the matrix, in which ZrC acted as a main composition of the resulting composites. The results showed that carbon matrix reacted preferentially with Si of Zr-8.8Si alloy, which caused the formation of SiC first and then ZrC. The designed carbon coating by pyrolysis prevented the severe reaction between fibers and the melt. The composites could be more dense and uniform with the bending strength of 53.3 MPa, when preforms had a high open porosity (47.2%) with small size pores (10-40 μm).