Solid Solution Strengthening and Softening Due to Collective Nanocrystalline Deformation Physics

TL;DR

This paper investigates how alloying influences the strength of nanocrystalline copper alloys, revealing both strengthening and softening effects linked to changes in elastic modulus and collective grain boundary deformation physics.

Contribution

It introduces a molecular dynamics simulation study showing how alloying affects nanocrystalline strength through elastic modulus modifications and collective deformation mechanisms.

Findings

Solid solution effects can both strengthen and soften nanocrystalline metals.

Strength trends are governed by changes in elastic modulus due to alloying.

Behavior aligns with collective grain boundary deformation physics.

Abstract

Solid solution effects on the strength of the finest nanocrystalline grain sizes are studied with molecular dynamics simulations of different Cu-based alloys. We find evidence of both solid solution strengthening and softening, with trends in strength controlled by how alloying affects the elastic modulus of the material. This behavior is consistent with a shift to collective grain boundary deformation physics, and provides a link between the mechanical behavior of very fine-grained nanocrystalline metals and metallic glasses.