• After seven ARB cycles, the 6061 Al/Cu composite achieved a tensile strength of 416 MPa with an elongation of 6.7%.
• The strength enhancement is primarily due to work hardening and grain refinement, with no brittle intermetallic compounds at the interface.
• Interfacial bonding improved with increasing ARB cycles, attributed to the small hardness difference between Al and Cu promoting uniform plastic deformation.
• Strain localization from differing work hardening responses led to shear band formation after seven cycles, reducing plasticity.