Enhancement of Plasticity of Highly Density-Fluctuated Cu-Zr Amorphous Alloy

抄録

This study explores the plastic deformability of highly density-fluctuated states due to the different thermal quenching process of the binary amorphous metals, Zr₆₇Cu₃₃, with embedded nanocrystals, Zr₂Cu. To know the effect of local structural fluctuation, we prepare 5 computational models with Zr₂Cu-nanocrystals that undergo rapid heat up and cool down. The region of nanocrystals is corresponding to the dense area because the intrinsic density of crystal is greater than that of amorphous structure. Due to the distribution of nanocrystals, the artificially constructed models have highly density-fluctuated structures (called “structural-inhomogeneity”). Strain localization during plastic deformation is much retarded at structural-inhomogeneous model in tensile loading. We found that structural-inhomogeneity promotes more homogenous deformation (call “deformable-homogeneity”, that is, retarded strain localization) even in globally recognized elastic region, while structural-homogeneity (almost close to pure amorphous structure) makes catastrophic inhomogeneous deformation (catastrophic shear band).