Dynamic Plastic Deformation Delocalization in FCC Solid Solution Metals

TL;DR

This paper introduces a new dynamic delocalization mechanism in FCC alloys that promotes plasticity homogenization, improving fatigue strength and offering a novel approach to designing more durable metallic materials.

Contribution

It identifies a new dynamic plastic deformation delocalization mechanism in FCC alloys that enhances mechanical performance and fatigue strength.

Findings

Mechanism occurs within a narrow stacking fault energy range.

Competing deformation modes include nanoscale twinning and slip.

Activation significantly improves fatigue strength.

Abstract

Metallic materials undergo irreversible deformation under mechanical loading, leading to intense local plastic localization that reduces their mechanical performance. We identify a new mechanism of plastic deformation localization that dynamically promotes the homogenization of plasticity in face-centered cubic solid solution-strengthened metallic alloys. We observe that this mechanism occurs within a narrow range of stacking fault energies and involves competing deformation between nanoscale twinning and slip. This phenomenon is attributed to a new mechanism referred to as dynamic plastic deformation delocalization, which opens a new design space for enhancing the mechanical performance of metallic materials. We demonstrate that the activation of this mechanism has a significant impact on fatigue properties, greatly enhancing fatigue strength when it occurs.