Abstract:

Continuous carbon fiber reinforced silicon carbide composites were fabricated with three dimensional preform by isothermal/isobaric chemical vapor infiltration. For the composites without pyrolytic carbon interface, the mechanical properties were increased with the density which included flexural strength and modulus, compressive strength and modulus, fracture toughness, and shear stress. However, the high density composites exhibited brittle fracture behavior because of strong bonding between both carbon fiber/silicon carbide matrix and carbon fiber bundless/bundle. Pyrolytic carbon interface was beneficial to fiber pull out, but brittle fracture in the fiber bundle was also observed because of the poor crystallization of pyrolytic carbon interface.

Key words: carbon?silicon carbide compo sites, microstructure, mechanical properties