Dislocation Cellular Structures

这是对细胞位错作用的基础研究 材料的变形和断裂中的结构。 是 这是以前关于基本机制的工作的产物， 控制胞状位错的稳态响应 疲劳产生的结构。 由于位错细胞 微观结构及其行为是 不均匀结构和不均匀行为， 描述了许多韧性晶体的变形 材料，这项工作的范围扩大到研究 位错胞状微观结构的现象。 从 从理论的角度来看，解决了几个问题，如 内部压力的发展，稳定的力量，导致 一个动态的稳定状态，细胞结构的演变， 受限制的随机位错活动，细胞壁的运动， 位错滑移和动态回复的详细机制 以及导致断裂的不稳定性的开始。 在实验上，这个项目解决了两个被认为是 是与细胞结构相关的最重要的问题， 可以通过实验解决，即变形的影响 细胞结构（或它们的缺乏）在断裂韧性和 部分（或恢复）退火对性能的影响 等温形成的胞状位错结构。 前 将是非常有价值的骨折社区和其正在进行的 屏蔽概念的审查，而后者将 解决空缺和内部压力对 观察到的疲劳金属的机械响应。

This is a fundamental study of the role of cellular dislocation structures in the deformation and fracture of materials. It is an outgrowth of previous work on the fundamental mechanisms controlling the steady-state response of cellular dislocation structures produced by fatigue. Since dislocation cellular microstructures and their behaviors are archetypical of the inhomogeneous structures and inhomogeneous behaviors that characterize the deformation of many ductile crystalline materials, the scope of this work is broadened to study dislocation cellular microstructures as phenomena. From the theoretical point of view, several issues are addressed, such as internal stress development, the stabilizing forces that lead to a dynamic steady state, the evolution of cell structures from restricted random dislocation activity, the motion of cell walls, the detailed dislocation mechanisms for slip and dynamic recovery and the onset of instabilities that lead to fracture. Experimentally, this project addresses two of what are believed to be the most significant issues related to cell structures that can be settled experimentally, namely the effects of deformation cell structures (or their absence) in fracture toughness and the effects of partial (or recovery) anneals on the behavior of isothermally formed cellular dislocation structures. The former will be very valuable to the fracture community and its ongoing examination of the shielding concept, while the latter will address the contribution of vacancies and internal stresses to the observed mechanical response of fatigued metals.