USING COATED CERAMIC PARTICLES TO INCREASE WEAR-RESISTANCE IN HIGH-SPEED STEELS

The use of chemical-vapor-deposition (CVD)-coated ceramic particle rei nforcements in metal-matrix composites allows the control of reactivit y at the particle/matrix interface. Wear-resistant, high-speed, steel- based composites containing uncoated Al2O3, uncoated TiC, and CVD-coat ed Al2O3 were liquid-phase sintered and characterized using pin-on-dis k wear testing. TiC or TiN CVD coating of Al2O3 resulted in a porosity decrease at the particle/matrix interface in addition to better ceram ic/metal cohesion due to improved wettability. Lower wear rates were o btained with the composites containing TiC- or TiN-coated Al2O3.