Fabrication and application of laminated SiC_w/SiC structure ceramics

Tape casting (TC) combined with chemical vapor infiltration (CVI) was proposed to fabricate laminated SiC_w/SiC structural ceramics, the advantages of TC-CVI were analyzed and the strengthening/toughening mechanisms and the application of the ceramics were investigated. The results showed that this method can increase strength of the ceramics by increasing their volume fraction and reducing the damage of SiC whiskers, and increase toughness of the ceramics by controlling the interfacial bonding between whiskers and matrix and inter-laminar bonding between layers. Comparing with laminated structural ceramics fabricated by hot-press sintering method, laminated SiC_w/SiC structural ceramics fabricated by TC-CVI had 40 vol% whiskers, in which the main toughening mechanisms of the ceramics were interlaminar and interfacial crack deflection and bridging and whisker pull-out. The ceramics had higher flexural strength, tensile strength and fracture toughness, and showed a good linear deformation behavior. TC-CVI process provides a feasible method for fabrication of aero engine blade.