Subsurface structural evolution and wear lip formation on copper single crystals under unlubricated sliding conditions

The crystalline lattice reorientation in copper single crystals resulted from friction-induced subsurface deformation has been studied by means of electron back scattering diffraction as well as optical microscopy. The results have been compared to those obtained earlier in uniaxial compression. The copper single crystals oriented by their normal load forces either along [110] or [11¯1¯] have been subjected to sliding tests during which the friction force direction was varied to assess the friction force orientation dependence on the crystalline lattice reorientation and segmentation. The results of dry sliding tests showed that the plastic deformation in copper single crystals depended on the crystal's orientation with respect to both normal and friction forces. Crystalline lattice reorientation in wear lip formation has been studied including reorientation by ridge-kink formations.