Plastic deformation of silicon during contact sliding at ambient temperature

Evidence of plastic deformation during contact sliding of silicon under relatively low loads at room temperature is presented. Sapphire spheres were slid against Si (1 0 0) under various normal loads at temperatures above and below the critical temperature. Upon chemical etching, pits that are attributed to dislocations developed along the sliding track for all experiments. This suggests that plastic deformation can readily take place in covalent solids, such as silicon, even at temperatures far below the critical temperature. The results of this work support the view that frictional force and energy dissipation are largely caused by plastic deformation of the materials near the sliding contact even under relatively low loads.