预加载对块体非晶合金弹性极限的影响

s a new category of advanced materials with high elasticity for structural applications, the strength of bulk amorphous alloys should be assessed by their elastic limit. In this paper, the mechanical behavior of Zr52.5Cu17.9Ni14.6Al10Ti5 bulk amorphous alloy was investigated under uniaxial compression using as-cast bulk-sized specimens. It was found that the elastic limit of the alloy on macroscale specimens is evidently lower than its apparent yield strength because of casting defect effect, and the introduction of artificial notches with larger sizes on the specimens makes the difference between the two kinds of strength further increased. The decreased elastic limit was caused by the local shear-banding deformation around casting defects or artificial notches. "Apparent strain hardening" phenomenon occurred in the pre-yield region of the macroscale specimens, which was correlated with the microstructural softening and the mitigation of stress concentration intensity around defects or notches during local shear-banding deformation. By isotropic preloading at the stress level near apparent yield stress, the elastic limit can be obviously increased. The macroscale hardening phenomenon after preloading was induced by the microscale softening in the alloy during preloading. This approach shows an easy way to enhance the elastic limit of bulk amorphous alloys for engineering applications.