An n-body W–Cu potential is constructed under the framework of the embedded-atom method by means of a proposed function of the cross potential. This W–Cu potential is realistic to reproduce mechanical property and structural stability of WCu solid solutions within the entire composition range, and has better performances than the three W–Cu potentials already published in the literature. Based on this W–Cu potential, molecular dynamics simulation is conducted to reveal the mechanical property and dislocation evolution of the bilayer structure between pure W and W0.7Cu0.3 solid solution. It is found that the formation of the interface improves the strength of the W0.7Cu0.3 solid solutions along tensile loading perpendicular to the interface, as the interface impedes the evolution of the dislocation lines from the W0.7Cu0.3 solid solutions to the W part. Simulation also reveals that the interface has an important effect to significantly reduce the tensile strength and critical strain of W along the tensile loading parallel to the interface, which is intrinsically due to the slip of the edge or screw dislocations at low strains as a result of the lattice mismatch.

The propagation of a fatigue crack in and the intergranular corrosion (IGC) behaviour of Al–Zn–Mg–Cu alloys with and without the addition of Sn were tested, and the microstructures of these alloys were further analysed using optical microscopy, scanning electron microscopy and transmission electron microscopy. It was found that the addition of Sn refines the solution aging grain size and reduces the width of the precipitation free zones, which results in reinforcement of the alloy's fatigue crack propagation resistance. In addition, discontinuous distribution of grain boundary precipitates in the Sn containing alloy directly leads to a higher IGC resistance.