Microstructure evolution and anti-wear mechanism of Cu film fabricated by magnetron sputtering deposition

• Magnetron sputtering method is used to prepare Cu film. • FIB cutting is firstly used combined with EBSD to analyze the worn surface. • Grain refinement effect can improve the anti-wear properties of Cu film. • GP zones and Nano-twinned copper are found in the pole surface of wear scar. • The evolution from the GP zones to stacking faults structures during friction might improve the anti-wear properties. Copper (Cu) film was fabricated by magnetron sputtering method, and then subjected to current-carrying friction experiments in this study. Plastic deformations were found in the surface of the wear scar. Focused Ion Beam (FIB) cutting technology was firstly used combined with the Electron Backscattered Diffraction (EBSD) to analyze the worn surface, and the results indicated that the original grains would be broken down into smaller grains during friction. Owing to the strengthening effect of grain refinement, the Cu film exhibited good anti-wear properties. The TEM pattern revealed that the Cu Columnar crystals grow along the direction of magnetron sputtering deposition and perpendicular to the direction of reciprocating friction. GP zones and Nano-twins were observed at the polar surface, and the GP zones would gradually transform to stacking faults structures during the friction.