Atomic-scale mechanisms of tension-compression asymmetry in a metallic glass

作者：Chen, L. Y.^*; Li, B. Z.; Wang, X. D.; Jiang, F.; Ren, Y.; Liaw, P. K.; Jiang, J. Z.

来源：Acta Materialia, 2013, 61(6): 1843-1850.

DOI：10.1016/j.actamat.2012.11.054

• Metallic glasses
• Mechanical behavior
• X-ray diffraction
• Synchrotron radiation
• Crystallization

Materials exhibit a tension-compression asymmetry in terms of plasticity. This phenomenon is usually interpreted by continuum mechanics, which neglects the stress-induced structure change. Here we investigated the structure change of a metallic glass of Zr46.5CU45 Al7Ti1.5 (in at.%) under both tensile and compressive stresses by in situ loading and high-energy X-ray scattering. A relationship between the stress-induced structure change and the extraordinary tension-compression asymmetry of plasticity in the metallic glass is presented. Another interesting phenomenon is that the metallic glass also exhibits tension-compression asymmetry in terms of crystallization. The influence of the stress-induced structure change on the crystallization behavior of metallic glasses is discussed. The results obtained here reveal the structure evolution of a metallic glass under both tensile and compressive stresses, and might provide a new perspective on the tension-compression asymmetry in the structure of amorphous solids.

• 出版日期2013-4
• 单位浙江大学