非晶合金塑脆断裂转变的控制参数

材料的塑脆断裂转变及机理一直以来都是材料和力学领域的研究热点.近百年来,针对晶体材料的塑脆行为,相继发展了一系列弹、塑性的起裂临界判据及塑脆表征参数.非晶合金作为近年来涌现的一类新型结构材料,因具有优异的力学性能,在国防、空天等领域显示出广阔的应用前景.然而,该材料变形局部化剪切带导致的室温低塑性极大地限制了其工程应用.因此,弄清非晶合金的塑脆断裂行为及转变条件显得尤为迫切.在传统理论的基础上,结合非晶合金固有的特性,目前已发展了塑脆转变的单参数和双参数控制理论.本文将对这些理论进行简要的回顾,进一步揭示这些控制参数的相互关联及非晶合金塑脆转变的实质.

Inherent parameters governing ductile-brittle transition in metallic glasses

The ductile-brittle transition and its mechanism are the hot research topics in the field of material and mechanics.In recent hundred years,the critical conditions for cracking and the governing parameters on ductility have developed for crystalline solids.Metallic glasses（MGs） as an emerging class of structural materials in recent years,show a broad potential applications due to their excellent mechanical properties.However,the low plasticity caused by highly strain localization greatly restrains them from engineering application.Therefore,to clarify the plastic behavior and the ductile-brittle transition in MGs becomes significant.Based on the classical theories,researchers have developed some important conditions to predict the plasticity in MGs,by taking their inherent properties into account.These theories usually include single or two governing parameters.In this paper,a brief review is carried out on these previous work,and further the underlying correlations between these governing parameters and the physics behind the ductile-brittle transition are revealed.