Effect of Heterophase Interfaces on Microstructure and Crystallographic Texture Evolution during Rolling of Directionally Solidified Ag-Cu Eutectic Alloy

A directionally solidified Ag-Cu eutectic alloy was deformed by rolling to understand the role of heterophase interfaces on the deformation behavior of ultrafine and nanocrystalline face-centred cubic metals. During rolling, the initial 〈220〉 fibre texture was gradually shifted to a Brass type texture for both Ag and Cu phases. More interestingly, a similar path of texture evolution was observed for both the phases at all strain levels. The in-depth transmission electron microscopy analysis revealed that the Ag lamellae deformed primarily by twinning, while the Cu lamellae deformed by twinning and dislocation slip. Furthermore, the special cube-on-cube and twin heterophase interfaces facilitated co-deformation and co-rotation of the adjacent Ag and Cu lamella due to a strong latent hardening effect, which stimulated a similar texture evolution for both phases.