Superior tensile ductility in bulk metallic glass with gradient amorphous structure.
Superior tensile ductility in bulk metallic glass with gradient amorphous structure.
复制标题
具有梯度非晶结构的块状金属玻璃具有优异的拉伸延展性
DOI：
10.1038/srep04757
复制
发表时间：
2014-04-23
影响因子：
4.6
通讯作者：
Lu J
中科院分区：
文献类型：
--
作者：
Wang Q;Yang Y;Jiang H;Liu CT;Ruan HH;Lu J
几个世纪以来，由于结构玻璃缺乏拉伸延展性，结构玻璃一直被认为是一种坚固但固有的“脆性”材料。然而，在这里，我们报告的大块金属玻璃表现出高强度的~2 GPa和前所未有的拉伸伸长率的2-4%，在室温下。 我们的实验表明，强烈的结构演变可以触发这些玻璃通过仔细控制的表面机械研磨处理，导致整个样品厚度的梯度非晶微结构的形成。结果，工程化的非晶微结构有效地促进了多个剪切带，同时延迟了块状金属玻璃中的空穴，从而导致上级拉伸延展性。我们的研究结果揭示了单片大块金属玻璃中不寻常的加工硬化机制，并展示了一种适用于生产大尺寸，超强和可拉伸结构玻璃的有前途但低成本的策略。
Over centuries, structural glasses have been deemed as a strong yet inherently ‘brittle’ material due to their lack of tensile ductility. However, here we report bulk metallic glasses exhibiting both a high strength of ~2 GPa and an unprecedented tensile elongation of 2–4% at room temperature. Our experiments have demonstrated that intense structural evolution can be triggered in theses glasses by the carefully controlled surface mechanical attrition treatment, leading to the formation of gradient amorphous microstructures across the sample thickness. As a result, the engineered amorphous microstructures effectively promote multiple shear banding while delay cavitation in the bulk metallic glass, thus resulting in superior tensile ductility. The outcome of our research uncovers an unusual work-hardening mechanism in monolithic bulk metallic glasses and demonstrates a promising yet low-cost strategy suitable for producing large-sized, ultra-strong and stretchable structural glasses.