ABSTRACT
Scratch testing represents a test form where some degree of controlled abrasive wear or adhesion between one material medium to another can be quantified un der controlled conditions. In conventional scratch testing a diamond stylus is drawn across a sample under either a constant or progressively increasing normal load. The minimum or critical load point at which the onset of coating delamina tion occurs is used as a semi-quantitative measure of practical adhesion. The scratch test on a coated sample may be analyzed in terms of three contributions: (1) a ploughing contribution that depends on the indentation stress field and the effective flow stress in the surface region, (2) an interfacial friction contribution due to interactions at the indenter-sample interface, and (3) an internal stress con tribution as any internal stress will oppose the passage of the indenter through the surface, thereby effectively modifying the surface flow stress [1-3].
