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总览 评价 胡莉莉 * ， 唐鹏 （ 华中科技大学 力学系 工程结构分析与安全评定湖北省重点实验室，湖北省武汉市，430074； ） 摘要： 金属钨因其高强度高熔点的特性多用在高温高压甚至高应率的极端工作环境中。为研究钨在这样的极端环境中的力学行为，位错运动
胡莉莉*， 唐鹏
（
华中科技大学 力学系 工程结构分析与安全评定湖北省重点实验室，湖北省武汉市，430074； ）
摘要：
金属钨因其高强度高熔点的特性多用在高温高压甚至高应率的极端工作环境中。为研究钨在这样的极端环境中的力学行为，位错运动在其中的作用不可忽视。位错产生影响的关键之一在于其和晶界间的相互作用。而分子动力学模拟因其天然的高应变率的特性适合作为研究手段。对刃型位错，螺型位错和孪晶界相互作用的模拟显示，不同情况下的作用机理不一样。刃型位错可能会直接穿过孪晶界，在晶界上留下沿相反方向运动的残片。刃型位错也可能会被晶界阻塞，粘着在晶界上不再运动。螺型位错也会穿透孪晶界，在另一个晶粒内部沿对称方向即原滑移系运动，同时一部分沿原路反射回去。
关键词：
位错；晶界；高应变率；孪晶界
Hu Lili*， Tang Peng
（
Hubei Key Laboratory of Engineering Structural Analysis and Safety Assessment, Department of Mechanics, Huazhong University of Science & Technology, Wuhan Hubei, 430074； ）
Abstract：
Tungsten has high strength and high melting temperature, so it is usually applied in extreme conditions even with very high strain rate. To study the mechanical behavior of tungsten in such conditions, the influence of dislocation motion is very important. The influence of dislocations takes effect through different ways of which the interaction with grain boundaries is a very important one. Molecular dynamics simulation naturally has a very high strain rate and is suitable for this paper. The simulation considered the interaction between the edge dislocation and screw dislocation with a twin grain boundary. It is found that the interaction works in different ways. An edge dislocation can go over a twin boundary and leave residues on the bonundary that moves in opposite directions. Also an edge dislocation can be blocked by or attached to the twin boundary and does not move any more. A screw dislocation can penetrate the twin boundary and move in a symmetric direction in the other grain that is the same gliding plane. At the same time, part of the dislocation is reflected back.
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