# Strengthening of Al-Cu alloys by Guinier-Preston zones: predictions from atomistic simulations

## TL;DR

This paper presents a multiscale simulation approach combining molecular dynamics, static simulations, and transition state theory to predict the flow stress of Al-Cu alloys strengthened by Guinier-Preston zones, aligning well with experimental data.

## Contribution

It introduces a novel scale bridging strategy that integrates atomistic simulations with transition state theory to accurately predict alloy strengthening.

## Key findings

- Predicted flow stress aligns with experimental data.
- The model effectively captures thermal and athermal contributions.
- Atomistic simulations can reliably predict precipitate-strengthened alloy behavior.

## Abstract

A scale bridging strategy based in molecular statics and molecular dynamics simulations in combination with transition state theory has been developed to determine the flow stress of Al-Cu alloy containing Guinier-Preston zones. The athermal contribution to the flow stress was determined from the Taylor model, while the thermal contribution was obtained from the obstacle strength and the free energy barrier. These two magnitudes were obtained by means of molecular statics and molecular dynamics simulations of the interaction of edge dislocations with Guinier-Preston zones in two different orientations. The predictions of the model were compared with experimental data and were in reasonable agreement, showing the potential of atomistic simulations in combination with transition state theory to predict the flow stress of metallic alloys strengthened with precipitates.