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

摘要

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