位错、裂纹与断裂

DISLOCATION, CRACK AND FRACTURE

本文评述近些年来在位错、裂纹与断裂方面的研究进展.内容主要包括:①以屈服强度温度依赖性为例,讨论力学性能的结构敏感性,使其对位错芯结构与塑性之间的关系有一定的认识;②纯弹性断裂总是极少的,因之在加载应力作用下,裂纹顶端总是存在着或大或小的塑性区,存在着裂纹与位错的交互作用.这里以我们自己的工作为主,重点讨论裂端位错过程的研究结果.

This article reviews the recent advances in dislocation, crack and fracture. The main contents include:(1) Taking the temperature dependence of yield strength as an example, we discuss the structure sensitivity of mechanical property in order to understand the relationship between the structure of dislocation core and plasticity; (2) Pure elastic fracture is always rare, so th at under the action of stress,a plastic zone(large or small),and interactions between crack and dislocations always exist at the crack tip. Here, mainly based on our own work, we discuss the research result of the dislocation process at crack tip.