Interface Design and a New Process to Produce SiC(w)/Si3N4 Ceramic Composite

There are two kinds of interfaces in the Si3N4 ceramic matrix composite reinforced by SiC whiskers, one is the grain boundary between the Si3N4 matrix grains, another one is the interface between Si3N4 grains and SiC whiskers. In this paper, SiC(w)/Si3N4 composite was prepared by adding two different groups of additives to optimize these two different kinds of interfaces. Extreme high bending strength and fracture toughness, about 1000–1100 MPa and 10.5–11.5 MPa m1/2, respectively, were obtained. The effects of the additives and the process were discussed in detail.