Tribologically induced crystal rotation kinematics revealed by electron backscatter diffraction

Tribological loading of metals induces microstructural changes by dislocation-mediated plastic deformation. During continued sliding, combined shear and lattice rotation result in the formation crystallographic textures which influence friction wear at sliding interface. In order to elucidate fundamental kinematics involved this process during early stages we conducted unlubricated, linear single pass experiments on a copper bicrystal using sapphire spheres. Electron backscatter diffraction (EBSD) performed directly bulk surface tracks vicinity grain boundary reveals crystal rotations approximately up 35°. Predominantly, tribologically induced appear be kinematically constrained around transverse direction (TD) occur both grains, irrespective load (2 8 N). We demonstrate that inverting (SD) inverts sense rotation, but does not change principal nature for majority indexed EBSD data. A lower proportion rotates much farther TD (roughly 90°), accompanied superimposed ±SD. Analysis orientation exert systematic how are accommodated. This is rationalized terms geometry, anisotropic track profiles slip traces. Under specific conditions, twinning observed. These detailed insights into provide important guidance applied research targeting materials with superior tribological properties.