Promoting abnormal grain growth in Fe-based shape memory alloys through compositional adjustments
Promoting abnormal grain growth in Fe-based shape memory alloys through compositional adjustments
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DOI：
10.1038/s41467-019-10308-8
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发表时间：
2019-05
影响因子：
16.6
通讯作者：
M. Vollmer;T. Arold;M. Kriegel;V. Klemm;S. Degener;J. Freudenberger;T. Niendorf
中科院分区：
文献类型：
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作者：
M. Vollmer;T. Arold;M. Kriegel;V. Klemm;S. Degener;J. Freudenberger;T. Niendorf
铁基形状记忆合金由于其成本效益和使用钢铁工业传统加工路线的可能性而成为大规模结构应用的有希望的候选者。然而，最近开发的合金体系，如Fe-Mn-Al-Ni，如果晶粒没有完全覆盖样品截面，则可恢复性很低。为了克服这个问题，我们发现少量的钛添加到Fe-Mn-Al-Ni中，由于亚晶粒尺寸的细化，显著地促进了异常晶粒的生长，而少量的铬则对异常晶粒的生长有很强的抑制作用。通过剪裁和促进异常晶粒生长，可以获得非常大的单晶棒。我们期望本研究关于异常晶粒生长的基本机制和化学成分的作用的发现可以应用于具有类似显微组织特征的其他合金体系。
Iron-based shape memory alloys are promising candidates for large-scale structural applications due to their cost efficiency and the possibility of using conventional processing routes from the steel industry. However, recently developed alloy systems like Fe–Mn–Al–Ni suffer from low recoverability if the grains do not completely cover the sample cross-section. To overcome this issue, here we show that small amounts of titanium added to Fe–Mn–Al–Ni significantly enhance abnormal grain growth due to a considerable refinement of the subgrain sizes, whereas small amounts of chromium lead to a strong inhibition of abnormal grain growth. By tailoring and promoting abnormal grain growth it is possible to obtain very large single crystalline bars. We expect that the findings of the present study regarding the elementary mechanisms of abnormal grain growth and the role of chemical composition can be applied to tailor other alloy systems with similar microstructural features.