Research Center for Structural Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan.
Sci Rep. 2018 Jan 12;8(1):656. doi: 10.1038/s41598-017-19124-w.
Magnesium and its alloys have the lowest density among structural metallic materials; thus, this light-weight metal has great potential for reducing the weight, for example, of vehicles and trains. However, due to its crystal structure, deformability is poor; in particular, under compressive stress. In this study, we modified magnesium with bismuth as an alloying element, which has the characteristics of being likely to form precipitates instead of grain boundary segregation. The Mg-Bi binary alloy showed excellent deformability and high absorption of energy in high-strain rate regimes at room temperature via contribution of grain boundary sliding. These properties, which are closely comparable to those of conventional middle-strength aluminum alloys (Al-Mg and Al-Mg-Si series alloys), have never been observed before in magnesium alloys. The development of such properties opens the door for not only academic but also industrial research in magnesium.
镁及其合金在结构金属材料中密度最低；因此，这种轻金属在减轻重量方面具有很大的潜力，例如在车辆和火车方面。然而，由于其晶体结构，延展性较差；特别是在压缩应力下。在这项研究中，我们用铋作为合金元素来改性镁，铋具有形成析出物而不是晶界偏析的特点。Mg-Bi 二元合金通过晶界滑动表现出优异的变形能力和在室温下高应变速率区的高能量吸收能力。这些性能与传统中强度铝合金（Al-Mg 和 Al-Mg-Si 系列合金）非常接近，在镁合金中从未观察到过。这些性能的发展不仅为镁合金的学术研究，也为工业研究开辟了道路。
