Temperature Dependence of the Dynamics of Portevin-Le Chatelier Effect in Al-2.5%Mg alloy

TL;DR

This study investigates how temperature influences the Portevin-Le Chatelier effect in Al-2.5%Mg alloy, revealing deterministic chaos and increased complexity at higher temperatures through nonlinear dynamical analysis.

Contribution

It provides new insights into the temperature-dependent dynamics of the PLC effect, including chaos and complexity in alloy deformation behavior.

Findings

Stress drop magnitude increases with temperature

Deterministic chaos is present across all temperatures

Dynamics become higher dimensional at 425K

Abstract

Tensile tests were carried out by deforming polycrystalline samples of Al-2.5%Mg alloy at four different temperatures in an intermediate strain rate regime of 2x10-4s-1 to 2x10-3s-1. The Portevin-Le Chatelier (PLC) effect was observed throughout the strain rate and temperature region. The mean cumulative stress drop magnitude and the mean reloading time exhibit an increasing trend with temperature which is attributed to the enhanced solute diffusion at higher temperature. The observed stress-time series data were analyzed using the nonlinear dynamical methods. From the analyses, we could establish the presence of deterministic chaos in the PLC effect throughout the temperature regime. The dynamics goes to higher dimension at a sufficiently high temperature of 425K but the complexity of the dynamics is not affected by the temperature.