Hot-pressed A12O3–SiC(–C) composites with polycarbosilane as the precursor

The processing and mechanical behavior of Al2O3–xSiC (–C) (x = 1, 2, 5, 10 wt.%, ASx and ASCx) composites prepared by in situ reaction synthesis SiC from polycarbosilane (PCS) were investigated. The composites were densified by hot pressing. The pyrolysis process of PCS, microstructure, phase structure and mechanical properties of sintered composites were analyzed. Fully dense structure was obtained, and it was found that the fracture toughness and strength were highly improved compared with monolithic Al2O3. The fracture toughness reached 5.1 MPa m1/2 in 1 wt.%SiC composite ASC1. AS1 showed 516 MPa of flexural strength.