Solid-state bonding between Al and Cu by vacuum hot pressing

Diffusion bonding between aluminum and copper was performed by vacuum hot pressing at temperatures between 623 and 923 K through two thermal processes: hot compression under the deformation rate of 0.2 mm/min for 10 min at pre-set temperatures, and additional pressing at 0.2 mm/min for 20 min during furnace cooling. After analyzing interface, the feasible diffusion bonding temperature was suggested as 823 K. The three major intermetallic layers generated during diffusion bonding process were identified as Al2Cu, AlCu+Al3Cu4 and Al4Cu9. Furthermore, local hardness values of Al2Cu, AlCu+Al3Cu4 and Al4Cu9 layers average at (4.97 +/- 0.05), (6.33 +/- 0.00) and (6.06 +/- 0.18) GPa, respectively.