Orientation Influence on Tensile Strain Hardening in Forged Plates of AA2014 Aluminium Alloy

Strain hardening is an effective strengthening method for alloys that requires plastic deformation of the material during manufacturing. The strength will significantly increase due to the number of dislocations formed during plastic flow of material. This study examines the plastic flow activity of forged plates of an AA2014 aluminium alloy with tensile test conditions. The effects of solution treatment and artificial ageing on strain hardening characteristics and tensile behaviour were investigated using tensile testing and scanning electron microscopy. Hollomon plastic flow relationship was employed for solution treated and age hardening conditions by experimental engineering stress- engineering strain data of the aluminium alloy AA2014. In both solution-treated and age-hardened conditions, the alloy displays three distinct strain hardening rate levels. The highest rate of strain hardening occurs both in solution-treated and age hardening conditions in regions with lower strain. It is also noted that specimens experience higher and lower strain hardening rates in the forging direction (Longitudinal, L) and perpendicular to the forging direction (Transverse, T) respectively in both solution-treated and age hardening conditions. In order to bring out the degree of in-plane anisotropy, test are conducted in L, L+45° (45° to L direction) and T in the plane of forging. Lower and higher magnification SEM images of the alloy under study, clearly exhibited that the ductile dimple fracture associated with a lower shear fracture contributions.