High compression performance of C_f/SiC-Al composites fabricated by CVI and vacuum pressure infiltration

摘要

The strengthening effect of aluminum (Al) alloy as the second phase matrix on C_f/SiC-Al composites was investigated, and microstructures and compression performance of the composites were characterized and tested. The results show that compressive strength and modulus of C_f/SiC-Al composites were 627±21.4 MPa and 98±2.4 GPa, respectively. Compared with C_f/SiC composites prepared by chemical vapor infiltration (CVI) process, the compressive strength increased by 34.8%, and the modulus increased by 8.9%. The introduction of Al alloy by vacuum pressure infiltration process significantly improved the ability of the composites to withstand pressure loads. However, due to the Al alloy filling in the inter-bundle pores inside C_f/SiC composites, the space for the fiber to be deformed by force was limited, and the length of the fiber extraction was shortened.