Variations of properties across plate thickness for Al alloy 7010
(1. Materials Laboratory, Airbus UK, Broughton, Chester CH4 0DR, UK;
2. Department of Engineering, The University of Liverpool, Liverpool L69 3GH, UK;
3. Materials and Process Group, Airbus UK, Filton, Bristol, BS99 7AR, UK)
2. Department of Engineering, The University of Liverpool, Liverpool L69 3GH, UK;
3. Materials and Process Group, Airbus UK, Filton, Bristol, BS99 7AR, UK)
Abstract: The variations of electrical conductivity and hardness across the thickness of an Al alloy 7010 plate under the temper condition T7651 were investigated. The electrical conductivity and hardness respond in a reciprocal manner. Cross-sectional slices of the plate subjected to re-solutionising/natural ageing and re-solutionising/artificial ageing show the similar tendencies in property changes as in the as-received raw material. This clearly suggests that the property inhomogeneity across the plate thickness is inherent of the manufacturing route. The differences in properties through the plate thickness are due to the changes in the concentrations of the strengthening alloying elements in the solid solution and the associated changes in microstructure; these are believed to be mainly due to the nature of plate solidification and prolonged high temperature during the rolling operation. The combination of electrical conductivity and hardness can be used as an integral quality property indicator for assessing inhomogeneity of thick products.
Key words: alloy 7010; electrical conductivity; hardness; plate thickness