Mechanical properties and microstructure evolutions of multilayered Al–Cu composites produced by accumulative roll bonding process and subsequent annealing

Abstract

In this investigation different thicknesses of Cu and Al strips were accumulative roll bonded (ARBed) to form five dissimilar multilayered Al–Cu composites. Also, to investigate the effect of annealing on the mechanical properties, selected ARBed composites were annealed at three different temperatures (300, 400 and 500°C) for four different periods (10, 30, 60 and 360min). Different microstructural characterizations were conducted on the produced composites. The results demonstrated that by increasing the amount of Cu in the composites, tensile strength improved while elongation deteriorated. By increasing the annealing time and temperature, the tensile strength of the composites was remarkably decreased, after which it was increased while the elongation was increased rapidly and then decreased. This behavior was considered to be due to the restoration of the work-hardened metallic layers as well as formation of intermetallic compounds during annealing process. Corresponding fracture surfaces also revealed a brittle fracture in most of the annealed composites.