Microstructure and mechanical properties of carbon fibre-reinforced alumina composites fabricated from sol

摘要

Alumina matrix composites reinforced with the laminated and stitched carbon fibre cloth preform were fabricated through the infiltration-drying-heating route using the sol with a high solid content as raw materials. The investigation was focussed on the characteristics of sol and the mechanical properties and high-temperature resistance of composites. with favourable sintering activity can be obtained after heat treatment of sol at . The as-received composites with a total porosity of 16.8% exhibit a flexural strength of 271.3 MPa and a notch toughness of 13.0 MPa , respectively. As a result of the evolution of interface and matrix, the flexural strength of composites is decreased by 28.5% after heat treatment at for 1 h under inert atmosphere. At the same time, fracture mode of composites is transformed from tough to brittle behaviour.