Strength and ductility of aluminium alloy AA7030

The influence of the texture, strain rate and temper on the behaviour of an extruded AA7030 aluminium alloy is studied by uniaxial tensile tests. The results show that the texture has a strong impact on plastic flow and ductility. However, its influence on yield strength, ultimate strength and strain-hardening capacity is less. The temper conditions strongly affect the yield and ultimate strengths and strain-hardening capability, while their influence on plastic flow is limited. It was also found that the strain rate does not have an important influence on the plastic flow and the yield strength in temper W. While the ultimate strength and strain-hardening decrease significantly with increasing strain rate, the ductility increases. A metallographic study found that failure occurs by shear band formation subsequent to diffuse and local necking. Microscopic voids are formed in coarse slip bands prior to crack initiation. Fracture surface observations show that there is a high density of two different dimple sizes.