非晶合金塑性形变基本单元模拟的研究进展

Review of Simulation Research on the Fundamental Unit for the Plastic Deformation of Metallic Glass

非晶合金因其独特的长程无序、短程有序的结构特征而呈现复杂多样的宏观塑性形变行为。目前非晶合金领域已经达成一个共识:非晶合金复杂多样的宏观塑性形变行为具有完全相同的微观"元过程",是一种能够承载剪切变形的局部原子瞬时重排过程,这一瞬时重排过程通常被称为"流动事件"。由于"流动事件"的尺寸较小,发生速度较快,现有的测试手段很难同时实现高时间和高空间的分辨率对其进行直接观测,所以目前人们通常采用模拟的方法来对其进行研究。主要介绍了目前研究非晶合金"流动事件"的模拟方法,并对这些模拟方法的优势和缺点进行了评述,最后简要展望了非晶合金塑性形变基本单元模拟研究需要重点关注的几个问题。

Due to their unique structural characteristics such as long-range disorder and short-range order, metallic glas- ses exhibit complex and diverse macroscopic plastic deformation behaviors. The field of amorphous alloy has currently reached a consensus ： complex and diverse macroscopic plastic deformation behaviors of metallic glasses have the same micro- scopic ＂unit process＂, which is a local rearrangement of atoms undergoing inelastic shear distortion to accommodate plastic deformation, commonly referred to as ＂flow event＂. Since the size of the ＂flow event＂ is too small and its occurrence is too fast, the existing testing methods, which are difficult to achieve high time and spatial resolutions at the same time, are hard to directly observe the ＂flow event＂. Thus, researchers often adopt simulation methods to carry on the research of the ＂flow event＂. In this paper, we briefly review these simulation methods as well as their advantages and disadvantages. Finally, we identify several important points that deserve further investigation in the simulation research of the fundamental unit for the plastic deformation of metallic glass.