ABRASIVE WEAR OF OXIDE MATRIX PARTICULATE COMPOSITES

The paper describes differences in wear mechanisms between tests conducted in dry and wet environments (Dry Sand Test and Miller Test) for composites with two matrices: alpha - alumina and tetragonal zirconia. Two types of reinforced phase were used -the oxide and tungsten carbide particles. The wear susceptibility values were measured for matrices and composites. The worn surface analysis allows to establish that second phase particle addition modifies significantly alumina microstructure. It causes the change of dominant wear mechanism and increases wear resistance. Wear properties of both composite types are distinctly different in spite of wear environment. It was established that incorporation of second phase grains into alumina matrix influences wear properties changes in high scale. Changes observed for zirconia based composites are not so spectacular but still significant. Results of performed tests suggest that investigated materials are predicted to work at different environments. The wear at wet environments seems to be the best area of application for zirconia composites. Alumina based materials show the best properties during dry abrasion. Performed wear tests show the difference in the efficiency of application particular inclusion type. Although, incorporation of carbide grains always improves composite properties, the best scale of the improvement is achieved when one use oxide inclusions - zirconia grains into alumina matrix and on the contrary, alumina grains into zirconia matrix. It couldn't be simple described to differences in phase properties because one can observe differences between the agglomeration level of carbide and oxide inclusions. Such microstructural differences cold be an important factor of property diversification.