FINITE-ELEMENT ANALYSIS OF ELASTOPLASTIC INDENTATION .2. APPLICATION TO HARD COATINGS

A finite element model previously described is used to analyze indentation of hard-face materials. The materials (substrate and coating) are supposed elastoplastic, the spherical indenter is elastic. The state of stress during indentation (including unloading) of hard-face materials (chromium layer on steel) is investigated in details. The tensile stresses which might lead to failure are especially discussed, and related with experiments showing fracture or delamination of the coating. The model also shows the influence of film thickness on surface and interface stresses.