Determination of coating residual stress alterations demonstrated in the case of annealed films and based on a FEM supported continuous simulation of the nanoindentation

A method to determine coating residual stress alterations induced by various mechanical or heat treatments is introduced in the present paper. The developed procedure is based on a FEM supported continuous simulation of the nanoindentation, enabling the determination of stress distribution development in the coating during the indenter penetration. Herewith, the principal and equivalent stresses at various positions in the coating material at the moment of its plastic deformation beginning can be calculated. A thermal or mechanical coating treatment affects these stresses, which in turn can be defined in every case by means of nanoindentations and its aforementioned FEM supported simulation. The difference of the equivalent stresses associated with concrete coating treatments correspond to the related equivalent residual stress alterations. Heat-treated coated cutting inserts with different film thickness, annealed for various annealing times revealed considerable internal stress modifications.