DEFECT ACTIVATION MECHANISM OF CREEP IN LA-BASED AMORPHOUS ALLOY

As a potential structural and functional material, the study of deformation behavior in amorphous alloys has consistently attracted widespread attention. The intrinsic correlation between mechanical/physical properties and the microstructural heterogeneity of amorphous alloy is an important issue in the field of the solid mechanics and solid physics. In the current work, La62Cu12Ni12Al14 amorphous alloy was selected as the model alloy, benefitting from the glass forming ability (GFA) and unique mechanical properties. The current work mainly focused on the creep deformation behavior of the La-based amorphous alloy. In parallel, the evolution of the activation of defects during the creep process was probed. In the framework of the stretched exponential equation and relaxation time spectrum, evolution of stretch exponent, characteristic relaxation time, and the distribution of relaxation time intensity in amorphous alloys over physical aging time were specifically investigated in order to probe the physical aging below the glass transition temperature on the creep behavior. The constitutive equation based on the quasi-point defects theory can be used to describe the creep deformation of amorphous alloys. The formation, expansion, and irreversible merging of shear microdomains were employed to provide a rational explanation for the evolution patterns of elastic, viscoelastic, and plastic deformation components. On the basis of the tensile creep behavior of amorphous alloy, the evolution in defect activation within amorphous alloys has been clarified, simultaneously, the research sheds new light on further investigating the microscopic origins of structural heterogeneity in amorphous alloys. © 2024 Chinese Society of Theoretical and Applied Mechanics. All rights reserved.