Interface-controlled creep in metallic glass composites

TL;DR

This study uses molecular dynamics simulations to investigate how interfaces in metallic glass composites influence creep behavior, revealing that interfaces can act as weak zones and affect deformation depending on their orientation.

Contribution

It demonstrates that interface orientation and structure significantly impact creep rates in metallic glass composites, a factor previously underexplored.

Findings

All composites show higher creep rates than homogeneous glass.

Interface orientation affects creep behavior due to Schmid factor variations.

Amorphous interface regions serve as preferential slip sites.

Abstract

In this work we present molecular dynamics simulations on the creep behavior of $\rm Cu_{64}Zr_{36}$ metallic glass composites. Surprisingly, all composites exhibit much higher creep rates than the homogeneous glass. The glass-crystal interface can be viewed as a weak interphase, where the activation barrier of shear transformation zones is lower than in the surrounding glass. We observe that the creep behavior of the composites does not only depend on the interface area but also on the orientation of the interface with respect to the loading axis. We propose an explanation in terms of different mean Schmid factors of the interfaces, with the amorphous interface regions acting as preferential slip sites.