TRIBOLOGICAL CHARACTERIZATION OF THIN, HARD COATINGS

The use of thin, hard coatings in tribological applications has become more widespread. Thus the need to fully understand the relationships between the intrinsic properties of the coating, the properties of the coating/substrate composite and the tribological performance of the composite in different tribological systems has become more pressing. The present paper contributes to this effort by presenting and discussing the use of a selected number of physical and mechanical tests to obtain a general characterization of the tribological properties of a coated material: its tribological profile. The tribological tests include dry sliding wear, solid particle erosion and microabrasion. Even if the emphasis of the present paper is put on tribological characterization of thin, hard coatings, some of the current techniques frequently employed to characterize some of the more general properties of a coating, e.g. thickness, hardness, adhesion, residual stress state, etc., are treated. Examples from tribology profile determination and general characterization are collected from PVD and CVD coating systems.