| 论文简介 |
In order to investigate the tribological property of GaN crystal at nano-scale, a series of molecular dynamics simulations of nanoscratch are carried out on the surfaces of c-GaN, a-GaN, and m-GaN. The key factors of scratch depth and scratch direction which greatly influence the deformation behavior are explored by analyzing the mechanical response, surface wear, and subsurface dislocation nucleation. The friction coefficient, wear rate, and total length of dislocations are all found to increase with the increasing of scratch depth. A clear directional dependence could be recognized for c-GaN, where the friction coefficient along the [10-10] direction is always lower than that along the [1-210] direction, and the wear rate along the [10-10] direction is higher than that along [1-210] direction, regardless of scratch depth. On the contrary, the directional dependence of wear rate and friction coefficient are unclear for the a-GaN and m-GaN. For the scratches at a specific depth, dislocations in the c-GaN are smallest in length and occupy the shallow positions close to the surface, while widely distributed dislocations could be observed in the m-GaN. |
(创新港)
