Wear and Erosion Resistant Ceramic Coatings

Abstract

Wear and erosion are processes resulting in the gradual removal of material in the contacting surfaces of bodies in relative motion. The application of hard coatings is one of the most prospective ways to reduce deleterious effects of wear on the lifetime of the components. Based on the details of the mechanisms of friction and related wear and erosion, the main mechanical properties of the material systems for wear and erosion resistant coatings are discussed first. Then it is shown that a proper combination of hardness, elastic modulus and toughness is required to reduce contributions of the main mechanisms involved in friction and wear processes. The possible ways for the control of these properties, especially hardness, in PVD coatings involve, besides selection of the system with high intrinsic hardness, intentional modifications of the composition and structure via alloying by various transition metals and various decomposition and precipitation processes, respectively.