Abstract Fast-forming superplastic aluminum-based alloys are in demand. A deep understanding of high-strain-rate superplasticity is essential for developing novel alloys with improved properties. Herein, we analyzed the superplastic deformation mechanisms of a novel fast-forming aluminum-based alloy. The strain-induced microstructural evolution of the bulk and that of the focused-ion-beam-gridded surfaces of samples, deformed at 0.2 s−1, were studied. The results indicated that both grain-boundary sliding and dislocation slip/creep contribute equally to the total strain during high-strain-rate superplastic deformation. Higher intragranular strains and dislocation activity result in dynamic recrystallization, which has a determining effect on the high-strain-rate superplastic deformation of the alloy.

中文翻译：

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高应变速率下超细晶铝基合金的晶界和晶内变形

摘要 需要快速成型的超塑性铝基合金。深入了解高应变率超塑性对于开发具有改进性能的新型合金至关重要。在此，我们分析了一种新型快速成形铝基合金的超塑性变形机制。研究了应变诱导的样品的体积和聚焦离子束网格表面的微观结构演变，在 0.2 s-1 时变形。结果表明，在高应变率超塑性变形过程中，晶界滑动和位错滑动/蠕变对总应变的贡献相等。较高的晶内应变和位错活动导致动态再结晶，这对合金的高应变率超塑性变形具有决定性影响。