Interfacial microstructure and bonding strength of copper/aluminum clad sheets produced by horizontal twin-roll casting and annealing

Abstract

The copper/aluminum (Cu/Al) clad sheets were produced on a horizontal twin-roll caster and annealed. The effects of annealing temperature on the interface and peel strength of the Cu/Al clad sheets were investigated. The interfacial microstructures of the as-cast and annealed reinforced clad sheets were analyzed. With the increase of annealing temperature, the growth of total intermetallic compound (IMC) layer accelerated, and the peel strength slightly increased and then decreased rapidly. For the as-cast and annealing reinforced clad sheets, the thicknesses of interface layers were less; the interfaces were mainly composed of two or three IMC grain layers; there are the almost coherent interfaces of Al2Cu/Al4Cu9, Al2Cu/Al and Al4Cu9/Cu. These structural characteristics of the interfaces can improve the peel strength of the clad sheets.