The spatial and temporal characteristics of propagating deformation bands in the Al-Mg alloy AA5182 in O temper were studied experimentally at room temperature. Tensile tests were carried out on flat specimens at strain rates in the range from 10−5 to 10−1 s−1. Digital image correlation (DIC) and digital infrared thermography (DIT) were applied to monitor the propagating bands. It was found that the material exhibits a sharp yield point, and Lüders bands were seen at all the strain rates. Jerky flow took place all along the Lüders plateau. It thus seems that the Portevin–Le Chatelier (PLC) effect starts at incipient yielding and that there is no critical strain. At the end of the Lüders plateau, PLC bands immediately started to propagate back and forth along the gage section of the specimen. The work hardening of the material decreased consistently with increasing strain rate, while the flow stress on the Lüders plateau was rather unaffected by the strain rate. This indicates that the dynamic strain aging (DSA) mainly affects the strength of the interaction between mobile and forest dislocations. The strain to necking was found to decrease gradually with strain rate for this alloy, which is consistent with the lower work-hardening rate at the higher strain rates.
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机译：在室温下通过实验研究了Al-Mg合金AA5182在O回火中传播的变形带的时空特征。在扁平试样上进行拉伸测试，应变率范围为10 -5 到10 -1 s -1 。使用数字图像相关（DIC）和数字红外热成像（DIT）来监测传播波段。发现该材料表现出尖锐的屈服点，并且在所有应变速率下均观察到了Lüders带。整个Lüders高原都发生了急流。因此，似乎Portevin-Le Chatelier（PLC）效应始于初期屈服，并且没有临界应变。在吕德斯高原的尽头，PLC带立即开始沿标本的量具部分来回传播。材料的加工硬化随着应变速率的增加而持续降低，而Lüders高原上的流动应力却不受应变速率的影响。这表明动态应变老化（DSA）主要影响移动位错与森林错位之间相互作用的强度。发现该合金的颈缩应变随着应变速率逐渐降低，这与较高应变速率下较低的加工硬化速率相一致。
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