SLIDING WEAR OF SILICON-CARBIDE TITANIUM BORIDE CERAMIC-MATRIX COMPOSITE

The tribological behavior of a SiC-TiB2 ceramic-matrix composite was evaluated using a pin-on-flat contact configuration in reciprocating sliding. A steady-state friction coefficient of about 0.55 and an average specific wear rate of about 2 x 10(-6) mm3.N-1.m-1 were measured. The mechanisms of material removal involved failure of the particle-matrix interface, resulting in particle pullout and chipping of the matrix material. The generated wear debris was often recycled through the contact interface, resulting in the production of submicrometer fine particles that reattached to the surface and were later removed in flake form. Transitions were observed in the specific wear rate from higher to lower values as sliding progressed. These transitions were accompanied by transitions in the nominal contact pressure.