Deformation in Metallic Glasses Studied by Synchrotron X-Ray Diffraction
Deformation in Metallic Glasses Studied by Synchrotron X-Ray Diffraction
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DOI：
10.3390/met6010022
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发表时间：
2016-01
期刊：
影响因子：
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通讯作者：
T. Egami;Y. Tong;W. Dmowski
中科院分区：
文献类型：
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作者：
T. Egami;Y. Tong;W. Dmowski
高机械强度是金属玻璃的上级性能之一，这使得它们作为结构材料具有前景。然而，理解强无序物质（如金属玻璃）的机械变形过程是非常困难的，因为即使是定性描述结构的努力也会受到晶体周期性的阻碍。尽管有这样的挑战，我们表明，在应力下的高能同步辐射X射线衍射测量，使用二维探测器加上各向异性对密度函数（PDF）分析，极大地促进了努力解开复杂的原子重排涉及的弹性，滞弹性和塑性变形的金属玻璃。尽管PDF只提供了关于两个原子之间的相关性的信息，而不是关于多体相关性的信息，这通常是阐明各种性质所必需的，但通过使用应力作为激发系统的手段，我们可以获得关于玻璃变形过程中原子结构和局部原子重排的性质的丰富信息。
High mechanical strength is one of the superior properties of metallic glasses which render them promising as a structural material. However, understanding the process of mechanical deformation in strongly disordered matter, such as metallic glass, is exceedingly difficult because even an effort to describe the structure qualitatively is hampered by the absence of crystalline periodicity. In spite of such challenges, we demonstrate that high-energy synchrotron X-ray diffraction measurement under stress, using a two-dimensional detector coupled with the anisotropic pair-density function (PDF) analysis, has greatly facilitated the effort of unraveling complex atomic rearrangements involved in the elastic, anelastic, and plastic deformation of metallic glasses. Even though PDF only provides information on the correlation between two atoms and not on many-body correlations, which are often necessary in elucidating various properties, by using stress as means of exciting the system we can garner rich information on the nature of the atomic structure and local atomic rearrangements during deformation in glasses.