Tension-Compression Asymmetry in AA2219: Effect of Temperature and Stress States

¹ Indian Institute of Technology, Bombay, 400076 India
² Materials and Mechanical Entity, Vikram Sarabhai Space Centre, Trivandrum - 695022, India

^* Corresponding author: sushil.mishra@iitb.ac.in

Abstract

The tension-compression asymmetry (TCA) in AA2219 alloy exhibits distinct characteristics under varying loading conditions and temperatures. In uniaxial loading at room temperature, compressive stresses consistently exceed tensile stresses due to forming larger GP zones and θ″ phases during compression, which effectively impede dislocation motion. However, at elevated temperatures, the strength of the alloy decreases in both tension and compression, with a more pronounced drop under compression. This is attributed to temperature-dependent mechanisms such as dynamic recrystallization, which dominates above 300°C, and severe plastic deformation affecting dislocation slip. Under biaxial loading at room temperature, the nature of TCA changes significantly. While uniaxial compression stresses are initially higher than tensile stresses, a transition occurs in biaxial conditions where compressive stresses decrease relative to tensile stresses. At equi-biaxial loading, the asymmetry becomes more pronounced, with tensile stresses exceeding compressive stresses. These findings highlight the complex interplay of stress state, temperature, and microstructural mechanisms in governing the TCA behavior of AA2219, providing valuable insights for applications involving diverse loading scenarios.