Abstract This study develops an Orowan precipitate hardening equation applicable to twin propagation. It is derived from a series of two dimensional dislocation dynamics simulations of a twin tip impinging upon a line of obstacles. When the number of twinning dislocations present is low, the Orowan stress increases with the number of twinning dislocations in the twin. When the number of twinning dislocations is high, the trailing dislocations do not partake in the critical initial bypass event, instead, they multiply the stress on those leading dislocations that do. The result is that bypass takes place at lower stresses when more twinning dislocations are present. A double super dislocation model provides a good description of the phenomenon. It is seen that particle size exerts a stronger role than in the conventional Orowan hardening equation and that there exists a number of twinning dislocations for which the Orowan stress is greatest. For alloy design using non-shearable precipitates, the basic objective of decreasing the inter-particle spacing on the twin plane remains most efficacious.

中文翻译：

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Mg 中机械孪晶的 Orowan 沉淀强化方程

摘要 本研究开发了适用于孪生传播的 Orowan 沉淀硬化方程。它源自对双尖端撞击障碍物线的一系列二维位错动力学模拟。当孪晶位错数量较少时，Orowan 应力随着孪晶中孪晶位错数量的增加而增加。当孪晶位错的数量很高时，尾随位错不会参与关键的初始旁路事件，相反，它们会增加那些参与的引导位错的压力。结果是当存在更多孪晶位错时，在较低应力下发生旁路。双超位错模型很好地描述了这种现象。可以看出，粒径比传统的 Orowan 硬化方程发挥更大的作用，并且存在许多 Orowan 应力最大的孪晶位错。对于使用不可剪切析出物的合金设计，减少双平面上的颗粒间距的基本目标仍然是最有效的。