Bulk metallic glasses: “Defects” determines performance

In the current work, the size effect to plasticity of the Zr₅₀Cu_40+xAl_10−x (x=0, and 2) bulk metallic glasses has been investigated experimentally. It is found that macroscopic plasticity are affected by different of leading factors. The mean stress drop of serrated flow is positively related to the number of weak regions. With greater number of weak regions, more pronounced stress drop occurs in the serrated flow process. The experimental results suggested that fewer number of weak regions lead to larger dimple patterns area. Besides, the average spacing of primary shear bands is associated with the weak regions and the position where shear bands terminate.