CERAMIC WEAR MAPS

Ceramic wear maps have been developed to elucidate the complex interac tions of the operating parameters, environments, and wear mechanisms. This paper summarizes these interactions for four ceramics, alumina, y ttria-doped zirconia, silicon carbide and silicon nitride. Wear maps o f these ceramics are systematically constructed using measured data un der dry sliding, water, and paraffin lubricated conditions. For each m aterial, different wear level regions and wear transition zones are id entified as a function of operating conditions and lubrication conditi ons. Wear mechanism studies performed within each wear region give ris e to the wear mechanism maps. These maps facilitate material compariso n and selection. The knowledge of wear, wear transitions, and wear mec hanisms for a material pair enables realistic wear model development. One outcome of this approach is the recognition that a single wear mod el for a material pair cannot cover all operating conditions and envir onments. As wear maps are constructed today, they are material pair sp ecific. Within a material Fair, there are microstructural dependence a nd surface properties influence. These parameters can change substanti ally for a given chemical composition of the material. Plow to incorpo rate these factors into the wear map research remains an issue. The se arch for a universal parameter such as the ''asperity temperature'' in Ashby's wear map continues in spite of mounting evidence that this ma y not be practical or feasible. But the hope remains that some paramet ers can be identified to normalize a large number of materials, operat ing conditions, and environments for tribological applications. System atic wear maps are the first steps in this direction.