Influence of reduction ratio on the interface microstructure and mechanical properties of roll-bonded Al/Cu sheets

Two-ply Al/Cu sheets were prepared via roll bonding with different reduction ratios. Al/Cu sheets fabricated below 50% of reduction ratio exhibited relatively equiaxed grains without interface reaction, which resulted in weak joint-bonding strength. However, both strong metallurgical bonding at interface and fine, elongated grains from constituent alloys adjacent to the interface were successfully introduced under the reduction ratio of 65%, leading to a strongly enhanced bonding strength of 17.1 N/mm together with an increased elongation up to fracture by 28%.