ABSTRACT
The nature of the fiber/matrix interface in a ceramic matrix composite is critical to the performance of the composite. As discussed in Chapter 3, several of the mechanisms for toughening that are operable in reinforced ceramics require debonding of the fibers. With strong interfacial bonding, a crack propagating through the matrix will continue through a fiber, if stress is sufficient. With weaker bonding, debonding can occur under stress, resulting in toughening by crack deflection, fiber bridging, and fiber pullout. This is in contrast to a typical metal matrix or polymer matrix composite, where the major goal is more often strengthening, not toughening. In this case, a stronger fiber/matrix bond results in good load transfer from the matrix to the fibers and the presence of the strong fibers results in a stronger material than the monolithic matrix.
