An analysis of the indentation test to determine the interface toughness in a weakly bonded thin film coating – substrate system

Abstract A study of the mechanics of indentation induced interface delamination is described for systems consisting of a ductile film on an elastic substrate. Special attention is paid to the properties of the interface between coating and substrate. The interface is modeled by the use of a cohesive zone model within the finite element method. Two cases are distinguished, weak interface case and strong interface case. For weak interfaces, buckling of the coating occurs. Existing methods for interface toughness evaluation are evaluated and an alternative method for the determination the interface toughness from indentation delamination experiments is proposed.