The effect of thermal history on the atomic structure and mechanical properties of amorphous alloys

Abstract

The influence of thermal processing on the potential energy, atomic structure, and mechanical properties of metallic glasses is examined using molecular dynamics simulations. We study the three-dimensional binary mixture, which was first relaxed near the glass transition temperature, and then rapidly cooled deep into the glass phase. It was found that glasses prepared at higher annealing temperatures are relocated to higher energy states and their average glass structure remains more disordered, as reflected in the shape of the pair correlation function. The results of mechanical testing demonstrate that both the shear modulus and yielding peak increase significantly when the annealing temperature approaches $T_g$ from above. Moreover, the shear modulus becomes a strong function of strain rate only for samples equilibrated at sufficiently high temperatures. Based on the spatial distribution of nonaffine displacements, we show that the deformation mode changes from brittle to ductile upon increasing annealing temperature. These results can be useful for the design and optimization of the fabrication processes of bulk glassy alloys with improved plasticity.

20 pages, 7 figures

References in corpus (6)

• Collective nonaffine displacements in amorphous materials during large-amplitude oscillatory shear
• Mechanical annealing of model glasses: Effects of strain amplitude and temperature
• Nonaffine rearrangements of atoms in deformed and quiescent binary glasses
• Aging and rejuvenation during elastostatic loading of amorphous alloys
• Accelerated relaxation in disordered solids under cyclic loading with alternating shear orientation
• Atomistic modeling of heat treatment processes for tuning the mechanical properties of disordered solids

Cited by in corpus (7)

• Shear band formation in amorphous materials under oscillatory shear deformation
• Spatiotemporal analysis of nonaffine displacements in disordered solids sheared across the yielding point
• Accelerated rejuvenation in metallic glasses subjected to elastostatic compression along alternating directions
• Accessing a broader range of energy states in metallic glasses by variable-amplitude oscillatory shear
• A delayed yielding transition in mechanically annealed binary glasses at finite temperature
• Cooling under applied stress rejuvenates amorphous alloys and enhances their ductility
• Shear band healing in amorphous materials by small-amplitude oscillatory shear deformation