Abstract
In case that two surfaces of machine elements which have surface roughness produced by grinding or turning are scratched each other, the wear occurs by repeated scratches between asperity tips or wear debris. Therefore, in order to elucidate the mechanism of friction or wear, the deformation mechanism caused by scratching of minute asperities should be revealed.
From the view point that it is effective to use single crystal of metallic or nonmetallic material to study this problem from the microscopic approaches on dislocation levels, in this study a smooth surface of KCl single crystal was scratched with a spherical indentor. As the scratch directions ‹110› and ‹100› were chosen. The deformation mechanism was discussed by observing the dislocation patterns on the scratched surface and on its cross section.
The results obtained are as follows:
(1) The width of the scratched track was larger in the ‹100› scrach than in ‹110› scratch, whereas the range of plastic deformation was larger in ‹110› scratch.
(2) The plastic deformation produced by scratch was composed of a continuous pattern of the deformations produced by indentation.
(3) The active slip system of dislocations was mainly {110}90, ‹110› on the scratched surface and {110}45, ‹110› on the cross section perpendicular to the surface, respectively.
