Classification of metallic glasses based on structural and dynamical heterogeneities by stress relaxation

通过应力弛豫方法基于结构和动力学非均匀性对金属玻璃进行分类（英文）

We show that the diverse dynamic responses of viscosity of the supercooled liquid near the glass transition temperature can be inherited to glassy state and expressed in the discrepancy of stress relaxation, demonstrating a structural heterogeneous basis for fragility. The metallic glasses with diverse dynamics and structural heterogeneities manifesting in different densities and distributions of flow units can be classified and characterized in terms of a parameter n, which can be readily determined through stress relaxation method and is comparable to the kinetic fragility m of the supercooled liquid. The parameter can classify diverse metallic glasses and also benefits for understanding the correlation between the structural and dynamical heterogeneities of the metallic glasses.

形成非晶的过冷液体在接近玻璃转变温度的动力学响应的多样性和非均匀性可以遗传到非晶玻璃态中,表现为结构非均匀性.这种结构非均匀性可以通过其应力弛豫的不同来表征.在此实验结果基础上,本文提出了一个可以容易地通过应力弛豫测量的参数n,以此参数来表征不同非晶合金的动力学和结构非均匀性的差异,参数n还能反映非晶体系的流变单元的密度和分布,因此可以用n来对不同脆度的非晶玻璃进行分类.研究还发现该参数n还和过冷液体动力学脆性参数m以及非晶泊松比有关,可能成为表征金属玻璃的动力学和结构非均匀、结构和性能关系,非晶本质的重要参数.