Strain hardening is a useful mechanism for improving mechanical properties in materials. This study investigates the strain‐hardening behavior of an AA6060 alloy processed by equal channel angular pressing (ECAP) up to 12 passes. Analysis by electron backscattered diffraction (EBSD) shows that the average geometrically necessary dislocations (GNDs) density increases continually up to the fourth pass and then saturates at a value of ≈1.85 × 10¹⁴ m⁻². Hollomon and Kocks–Mecking–Estrin (KME) analysis are used to investigate the strain‐hardening behavior of the resulting ultrafine‐grained alloy. Results indicate that the strain‐hardening capacity (H_C) and the strain‐hardening exponent (n) of all deformed specimens are lower in comparison with the as‐received condition. Moreover, the strain‐hardening rate fluctuates with the ECAP passes. First, it increases from the first ECAP pass up to the fourth pass, then diminishes up to the fifth pass, and finally, it increases again with further deformation. The difference in the strain‐hardening behavior of the ECAPed AA6060 is examined in terms of the grain size effect. It is shown that the strain‐hardening curves change notably with diminishing the grain size. In addition, the KME model is used to depict the storage and annihilation of dislocations in the ECAPed specimens.

中文翻译：

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等径角挤压AA6060-T6合金的应变硬化行为

应变硬化是改善材料机械性能的有用机制。这项研究研究了通过等通道角挤压（ECAP）加工多达12次的AA6060合金的应变硬化行为。通过电子背散射衍射（EBSD）进行的分析表明，平均几何必要位错（GNDs）密度持续增加直至第四次通过，然后达到≈1.85×10 ¹⁴  m ^-2的值。Hollomon和Kocks-Mecking-Estrin（KME）分析用于研究所得超细晶粒合金的应变硬化行为。结果表明，应变硬化能力（H _C）和应变硬化指数（n）所有变形的样本都比预期的情况要低。此外，应变硬化率随ECAP的通过而波动。首先，它从第一次ECAP通过增加到第四次通过，然后减小直到第五次通过，最后，随着进一步变形再次增加。根据晶粒尺寸效应检查了ECAPed AA6060的应变硬化行为差异。结果表明，随着晶粒尺寸的减小，应变硬化曲线发生显着变化。此外，KME模型用于描述ECAPed标本中位错的存储和an灭。