Hot deformation behavior and processing maps for an Al-Mg-Si-Zr-Mn alloy

Abstract

Isothermal compression tests were executed on an Al-Mg-Si-Zr-Mn alloy using a Gleeble-3800 thermo-mechanical simulator at temperatures from 400 to 550 °C and strain rates ranging from 1 to 0.001 s⁻¹. By analyzing the flow curves and characterizing the deformed microstructure, this study aimed to gain insights into the hot deformation behavior and hot workability. Utilizing the hyperbolic-sine sinusoidal model, a constitutive equation was derived, revealing an activation energy of hot deformation of 274 kJ/mol. The processing maps were constructed utilizing the dynamic material model, which highlighted the secure range of hot working conditions between 480 to 550 °C and 0.01–0.001 s⁻¹. The softening mechanism observed at relatively low deformation temperatures and high strain rates was primarily dynamic recovery, whereas the safe domain exhibited a combination of dynamically recovered (DRV) and recrystallized (DRX) grain structures. The results of the FEM simulation indicated a non-homogeneous distribution of stress and strain fields, with the highest effective values focused at the center of the sample. Furthermore, the FEM simulation unveiled a clear correlation between the evolution of DRV and DRX and the strain.