Mechanisms of Monotonic and Cyclic Deformation

本文研究了金属的非弹性变形以及疲劳和蠕变对结构演变的相关影响，而结构演变反过来又影响变形过程。该计划包括三个相关研究：(1)重新加载试验，以评估由力学阈值和非热应力参数表示的结构演变；(2)应变速率变化试验，研究疲劳过程中结构的恒定变形动力学；(3)设计应力变化试验，以区分分散强化合金中不同的蠕变理论处理。开发了基于力学的模型来提供变形的定量描述。本研究的主要目标是了解非弹性变形过程，以扩展现有结构材料的操作环境，开发具有改进性能的新材料，并更好地控制成型和制造操作。

This proposal examines inelastic deformation in metals and associated effects of fatigue and creep on structure evolution, which, in turn, influences the deformation process. The program consists of three related studies: (1) reloading tests to assess the evolution of structure as represented by the mechanical threshold and athermal stress parameters; (2) strain rate change tests to study the kinetics of constant structure deformation during fatigue; and (3) stress change tests designed to discriminate between different theoretical treatments of creep in dispersion-strengthened alloys. Mechanistically-based models are developed to provide quantitative descriptions of deformation. %%% The primary goal of this research is to gain understanding of inelastic deformation processes in order to extend the operating environments of existing structural materials, to develop new materials with improved properties, and to gain better control of forming and manufacturing operations.