Anisotropic deformation behavior of Al2024T351 aluminum alloy

Abstract

The objective of this work was to investigate the effects of material anisotropy on the yielding and hardening behavior of 2024T351 aluminum alloy using isotropic and anisotropic yield criteria. Anisotropy may be induced in a material during the manufacturing through processes like rolling or forging. This induced anisotropy gives rise to the concept of orientation-dependent material properties such as yield strength, ductility, strain hardening, fracture strength, or fatigue resistance. Inclusion of the effects of anisotropy is essential in correctly predicting the deformation behavior of a material. In this study, uniaxial tensile tests were first performed in all three rolling directions, L, T and S, for smooth bar specimens made from hot rolled plate of Al2024 alloy. The experimental results showed that the L- and T-directions yielded higher yield strengths and a greater percentage of elongation before fracture than the S-direction. Subsequently, finite element analysis of tensile specimens was performed using isotropic (von Mises) and anisotropic (Hill) yield criteria to predict the onset of yielding and hardening behaviors during the course of deformation. Hill's criterion perfectly fitted with the test data in the S-direction, but slightly underestimated the yield strength in L-direction. The results indicated that the Hill yield criterion is the most suitable one to predict the onset of yielding and hardening behaviors for 2024T351 aluminum alloy in all directions.