Effect of Annealing Holding Time on Microstructure, Interface Diffusion Behavior, and Deformation Behavior of Cu/Al Composite Foil After Secondary Micro-Rolling.

In this study, the Cu/Al composite foil with a thickness of 0.04 mm was prepared by a combination of secondary micro-rolling and intermediate annealing process. The influence of different holding times (40, 60, and 80 min) at an annealing temperature of 400 °C on the microstructure, interfacial diffusion behavior, and deformation behavior of the secondary micro-rolled Cu/Al composite foil was systematically investigated using scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD). The experimental results showed that as the holding time increased, the grain sizes of both Cu and Al in the first and second micro-rolled samples and the thickness of the interfacial diffusion layer were increased, meanwhile the interfacial intermetallic compounds were consistently identified as CuAl2, Cu4Al, and Cu9Al4 at different holding times. When the holding time reaches 80 min, (CuAl) appears in the secondary micro-rolled specimens. Furthermore, with the increase in holding time, the protrusion height of the edge profile and the degree of edge cracking in the secondary micro-rolled specimens increase, demonstrating that the edge deformation behavior of the material was significantly influenced by the holding time.