Molecular dynamics simulation of friction behavior on nanoscale textured surfaces

The nanoscale friction process of a rigid hemispherical tip sliding on a single crystal copper substrate was studied by using molecular dynamics simulations. Different surface textures were designed and used. The effects of the direction and the density of surface textures on the sliding friction were analyzed. Comparisons of the sliding friction with different texture direction show that the amplitude of the sliding friction is lower at 0° and 90° texture direction when the surface texture density is less than 50%. The phenomenon of slip deformation is discovered when the texture direction is as 45°. For 0°and 90° texture direction, the sliding friction increases with the increase of the surface texture density when the texture density has great difference. Compared with the smooth surface, the textured surface can reduce friction at 0° and 90° texture direction for lower texture density effectively. Employment of nanoscale surface texture has significant influence on the sliding friction, but it does not change the period of the sliding friction.