Kinking-Mediated Anomalous Strain Rate Sensitivity During Compression Deformation in a Fe–Cr–Al Alloy

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发表日期：

2025年4月24日

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Wei Luo,
jiabin Li,
xiaoshuai Wang,
Ding Zuo,
Jingze Cheng,
Ruiqian Zhang,
Huiqun Liu

摘要

In this work, an anomalous compression behavior at 300 °C was found in a Fe–Cr–Al alloy, where the stress value decreased with increasing the strain rate, presenting a counterintuitive strain rate sensitivity effect. The results indicate that variations in kinking activation are the primary contributors to this phenomenon. Kinking can reduce significantly the dislocation density within the kink bands (KBs) and occasionally turn the local crystal to soft orientation, leading to softening. At low strain rate, kinking predominantly occurs in grains with high Taylor factor values (hard orientation, such as < $110$ $110$ > or < $111$ $111$ >//compression direction), exhibiting notable orientation dependency. With increasing strain rate, kinking may activate in soft-oriented grains, while in hard-oriented grains, KBs form clusters with multiple types, sometimes with secondary KBs developing within primary KBs, indicating higher kinking activation and reduced orientation dependency.