Structures and Mechanical Properties of Al-Al <inf>2</inf> Cu Interfaces

Al-Cu eutectic composites are composed of α-Al and θ-Al 2 Cu phases. Al-Al 2 Cu interfaces play a crucial role in determining the deformation modes and mechanical properties of nanoscale Al-Cu composites. In this work, we studied the structures and properties of the (110)Al2Cu∥(111)Al interface and elucidated corresponding plastic deformation mechanisms by using atomistic simulations. The (110)Al2Cu∥(111)Al interface comprises three sets of Shockley partial dislocations that divide the interface into three types of coherent structures. The interface exhibits isotropic, low shear resistance corresponding to the easy gliding and threefold symmetry of interface dislocations. Under mechanical straining parallel to the interface, unusual slips occur on {011}Al2Cu planes. Such an unexpected shear mode in Al 2 Cu phase is ascribed to the slip continuity across the Al-Al 2 Cu interface and the dislocations deposited at Al-Al 2 Cu interfaces.