Mechanical load-induced interfacial failure of a thin film multilayer in nanoscratching and diamond lapping

•Deformation and removal mechanisms of a thin film multilayer in abrasive machining were revealed using nanoscratching and diamond lapping, with the aid of FEM analysis.•Nanoscratching and lapping tests showed that interfacial delamination was the primary failure mode during abrasive machining of the multilayer.•FEM analyses revealed that shear stress concentrated at interfaces was the main cause for interfacial delamination.•The study demonstrated that the deformation and removal of the thin film multilayer under nanoscratching and lapping exhibited similar characteristics. The deformation characteristics and interfacial failure of a multilayered thin film solar panel involved in nanoscratching and diamond lapping were systematically investigated, with the aid of finite element modelling (FEM) analysis. The interfacial delamination modes generated in nanoscratching exhibited similar characteristics to those induced by diamond lapping. The FEM stress analysis revealed that the interfacial failure involved in the two processes was attributed to the significantly high shear stress induced at the interface between two dissimilar materials. It was also found that the roughness values of both scratched and lapped surfaces were related to the penetration depth for an individual layer material, regardless other testing conditions. This study demonstrates that nanoscratching is a valuable tool for understanding the deformation and failure mechanisms of thin film multilayered structures involved in abrasive machining.