Microstructural evolution and bonding characteristics of Ag/Cu interface in Ag/Cu bimetallic strips fabricated via diffusion welding

The unclear interfacial characteristics of Ag/Cu interface during diffusion welding limit the improvement of mechanical properties of Ag/Cu bimetallic strips. The growth orientation and evolution of Ag and Cu crystals between Ag and Cu strips were investigated by electron backscatter diffraction (EBSD) analysis, and the interfacial properties of various Ag/Cu interfacial configurations were calculated using first-principles calculations to elucidate the diversified interfacial char-acteristics. Three interface bonding states, including Ag(100)/Cu(100), Ag(110)/Cu(110) and Ag(111)/Cu(111), were preferentially formed in Ag/Cu bimetallic strips during roll bonding. The intensity of Ag(100)/Cu(100) interface increases with the increasing deformation amounts during cold rolling, accompanied by the decreased intensity of Ag(110)/Cu(110) and Ag(111)/Cu(111) interfaces. The largest adsorption work and lowest interface energy of Ag(100)/Cu(100) interface at the “center” position reveal the transition from Ag(110)/Cu(110) and Ag(111)/Cu(111) interfaces to Ag(100)/Cu(100) interface.