Fabrication and mechanical properties of the SiC fiber reinforced oxide matrix composites

A sintered SiC (Tyranno-SA) fiber-reinforced MAS glass matrix composite was fabricated by using a slurry infiltration method and hot-pressing. The microstructure and mechanical properties were investigated. To prepare the preform, the MAS glass slurry including a dispersing agent was infiltrated into a bundle of the fibers. The preform was then hot-pressed under the conditions of 1473 K, 30 MPa, 3.6 ksec. A unidirectionally-reinforced oxide matrix composite with 50% Vf. of the fiber and a density of 2.84 g/cm³ was obtained. As the mechanical properties at room temperature, the three-point flexural strength and quasi-static adsorbed energy were 500 MPa and 6,000 J/m², respectively. Without graphite or an h-BN pre-coating on the surface of the fiber, pull-out and bridging of the fibers from the matrix was found, and this leads to a high value of the adsorbed energy. By TEM observation, nano-scale crystalline products were found between the fibers and the glass matrix. The push-out test reveals that this layer causes the appropriate debonding of the interface during the fracture process of the composite.