Evaluation of fracture processes on thin films by simulation of spherical indentation testing

ABSTRACT Recent studies propose using indentation testing as a tool to assess the mechanical characteristics of thin films, as well as evaluate possible cracking in systems that conjugate films with high hardness values deposited on metallic substrates in tribological solicitations. However, implementing the indentation technique to assess the behavior of these film/substrate systems, and their results continue to raise doubts in the scientific community. Because of these uncertainties in the studies of the indentation testing, the use of numerical analysis capable of evaluating stress and strain fields during the indentation cycle may help better interpret this test. As such, this study aimed to use the finite element method (FEM) to simulate indentation testing of Chronium Aluminum Nitride (CrAlN) high-hardness film deposited in a carbon steel substrate. Two different damage models were used to assess the fracture processes that occur in these testing. The first was the diffuse cracking model and the second the delamination model, both present in MARC™ finite element software. The fracture processes observed in these simulations were compared with other published results. Finally, the concomitant use of these two damage models was a new approach to the study of indentation testing damage in thin films.