Microstructural characterization and mechanical performance of an AA2024 aluminium alloy - Pure copper joint obtained by linear friction welding

The present work deals with the microstructural and mechanical characterization of an AA2024 - pure Cu linear friction weld. A thorough study of the microstructural features in close contact with the interface led to propose a phenomenological mechanism of material flow. The interface is covered by a discontinuous layer of intermetallic compounds. Al2Cu, AlCu, Al2Cu3 and more particularly Al4C9, were detected. Two metastable phases, i.e. an Al3Cu2 compound and an out-of-equilibrium Al solid solution containing 13 at.%Cu, were also identified at the interface and on the Al side, respectively. In accordance with the applied strain state during welding, ideal shear texture components were formed on both sides of the joint Due to the formation of large intermetallic compounds, the mechanical resistance of the joint remains to be improved. (C) 2016 Elsevier Ltd. All rights reserved.