位错滑移运动与运动阻力辨析

Analysis on Dislocation Slipping and Moving Resistance

对位错在点阵周期场中运动时需要克服的阻力,以及影响阻力大小的因素作了辨析和讨论。含有位错的晶体变形,确定无疑是位错在外力场作用下滑移运动的宏观结果。对位错在完整晶体中运动分析表明,派-纳力对温度十分敏感。一定温度下,位错并非仅处于某一势能水平。即使外力应力小于派纳力,位错也可以通过扭折侧向运动,且由于热起伏造成的能量隆起,进而侧向扩展,使位错更容易运动。

The resistance of dislocation needed to be overcome while it moves in the lattice periodic ield, and the influence fac tors are analyzed in this paper. The crystal deformation with dislocation is certainly the macro result comes from the sliding motion of disloca tion under the function of outside force field. The movement of dislocation in perfect crystal shows that Peierls - Nabarro force is very sensitivity to temperature. The dislocation is not just at one certain potential energy level under a certain temperature. Even though outside force stress is less than Peierls - Nabarro force, dislocation can still move sideways through kinking, and it will spread laterally due to energy uplift caused by heat fluctuation, so that the dislocation can move more easily.