Mechanical Behavior and Microstructure Evolution during Hot Torsion Deformation of Aluminum Alloy AA2219

Abstract

This study comprehensively analyzes the mechanical behavior and microstructural evolution of aluminum alloy AA2219-T87 undergoing high deformation and strain rates at elevated temperatures via hot torsion tests. An integrated experimental and modeling approach is employed, where a finite element model (FEM) is developed with ABAQUS to address local deformation and nonuniform temperature distribution along the specimen gauge section. A Johnson-Cook constitutive material model is calibrated based on the calculated and measured torque curves at different conditions. The grain structure distribution is characterized through optical microscopy and electron backscatter diffraction (EBSD) analysis. Combined with the ABAQUS calculated local thermomechanical conditions, microstructure modeling, using established literature-based equations, is established to provide insights into grain size distribution and recrystallization mechanisms. The calibrated material constitutive model, recrystallization model, and grain size model can be utilized to model various manufacturing processes, which involve hot deformation of aluminum alloys in the intermediate strain rate range of 14-78 s À1 . The constitutive model shows adequate matching of the experimental torque curves at 400, 450, and 500 °C. The recrystallization prediction model functions at over 94% accuracy and the grain size model provides an average deviation between predicted and measured grain size reduction of 11.5%.