Making metallic glasses plastic by control of residual stress
Making metallic glasses plastic by control of residual stress
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DOI：
10.1038/nmat1758
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发表时间：
2006-11-01
期刊：
影响因子：
41.2
通讯作者：
Greer, A. L.
中科院分区：
文献类型：
--
作者：
Zhang, Y.;Wang, W. H.;Greer, A. L.
现在许多组合物都可以批量生产(1-3)，金属玻璃在利用其屈服应力和屈服应变的结构应用中引起了人们的兴趣，而这些屈服应力和屈服应变对于金属材料来说异常高(4)。它们的适用性受到加工软化和剪切局部化导致的接近零拉伸延展性的限制。尽管金属玻璃可以表现出广泛的局部塑性，但从宏观上看它们实际上是脆性的，并且当前的许多研究都旨在提高其总体塑性。在硅酸盐玻璃和金属合金等各种传统工程材料中，我们可以通过控制引入表面压应力来提高机械性能(5-7)。在这里，我们证明，我们可以在块状金属玻璃中可控地诱导这种残余应力，并且它们可以改善机械性能，特别是塑性，但改进背后的机制与传统材料中的机制不同。
Metallic glasses, now that many compositions can be made in bulk(1-3), are of interest for structural applications exploiting their yield stress and yield strain, which are exceptionally high for metallic materials(4). Their applicability is limited by their near-zero tensile ductility resulting from work-softening and shear localization. Even though metallic glasses can show extensive local plasticity, macroscopically they can effectively be brittle, and much current research is directed at improving their general plasticity. In conventional engineering materials as diverse as silicate glasses and metallic alloys, we can improve mechanical properties by the controlled introduction of compressive surface stresses(5-7). Here we demonstrate that we can controllably induce such residual stresses in a bulk metallic glass, and that they improve the mechanical performance, in particular the plasticity, but that the mechanisms underlying the improvements are distinct from those operating in conventional materials.