On wear mechanisms and microstructural changes in nano-scratches of fcc metals

Sliding and scratching are fundamental tribological phenomena which affect the surface and surface-near zones of materials. To clarify ongoing tribological and microstructural mechanisms, a thorough analysis of three fcc materials (aluminium, austenitic steel and copper) was performed via nano-sliding and scratching at different load levels. Nanoindentation was used to evaluate the phases’ mechanical properties, namely hardness H, Young’s modulus E and the ratios H/E (yield strain) and H³/E2 (resistance against plastic indentation), which proved to be good measures to understand the abrasive wear behaviour. Electron backscatter diffraction (EBSD) measurements and focused ion beam (FIB) cross-sections of the scratches provided deeper insight into the degree of deformation and deformation induced phase changes.