Twin boundary and temperature effect on the scratching behavior in silicon

The nanotwinned structure effect on the scratching behavior of silicon is investigated by the molecular dynamics simulations. The temperature influence is further considered. Compared with the single crystal silicon, the higher average fiction force along with less fluctuation is exhibited during scratching along [111] direction in twinned structure. As the temperature increases, both the tangential force and the normal force can decrease, and the corresponding force reduction rate gradually slows down. The twin boundary and temperature have little effect on the surface morphology, however, play a great influence on the subsurface damage. At the room temperature, the damage mechanism is dominated by the local lattice distortion. The dislocation can be activated at high temperature. The twin boundary can be regarded as the dislocation nucleation source, absorption site or barrier wall, which can affect the dynamic evolution of dislocation. Overall, the nanotwinned structure serves as an important role in the friction property, which will be used for improving the wear resistance of silicon. [Display omitted]