Hot Deformation Behavior of AA3102 Aluminum Alloy: Constitutive Modeling, Microstructural Evolution and Numerical Simulation

Abstract

This study systematically investigates the hot deformation behavior and microstructural evolution of AA3102 aluminum alloy through isothermal uniaxial compression tests conducted at 400–550 °C and strain rates of 0.01–10 s−1. Previous studies on 3xxx-series Al–Mn alloys have mainly considered temperature and strain-rate effects while neglecting strain-dependent material parameter variations, limiting prediction accuracy under large deformation and obscuring dynamic softening mechanisms. Here, the experimental flow stress data were corrected for interfacial friction and adiabatic temperature rise. A sixth-order strain-compensated Arrhenius constitutive model was then developed to describe the coupled effects of temperature, strain rate, and strain. Full-strain-range power dissipation and flow instability maps were constructed using the dynamic material model, while optical microscopy and DEFORM-3D simulations were employed to clarify microstructural evolution and deformation inhomogeneity. The model achieved a correlation coefficient of 0.9841 and an average absolute relative error of 3.67%, demonstrating high predictive accuracy. No flow instability was detected within the investigated range, indicating excellent hot formability. The favorable compression-processing window was identified as 500–550 °C and 0.1–1 s−1, while the peak power-dissipation efficiency increased from 30.55% at ε = 0.2 to 32.90% at ε = 0.8. Optical-microstructural observations suggest that increasing temperature and decreasing strain rate are associated with an increasing contribution of dynamic recrystallization relative to dynamic recovery. Finite-element results further reveal pronounced spatial variations in strain, temperature, strain rate, and stress during compression. These findings provide baseline constitutive and thermomechanical information for subsequent AA3102 hot-extrusion optimization.