Tailoring of interface structure and mechanical properties in ARBed 1100/7075 laminated composites by cold rolling

Abstract

Aluminum alloy AA1100/AA7075 laminated plates were fabricated from accumulative roll bonding and subsequent cold rolling process. Interface of the Al/Al were carefully characterized by optical microscopy (OM) and scanning electron microscopy (SEM). Mechanical properties of the laminated plates were measured by tensile test. Experimental results showing the critical strain of the onset of plastic instability was acquired with increasing reduction in thickness during cold rolling. It was observed that 7075Al layers were necked and fractured as cold rolling reduction was increased, and the final structure consists of a higher volume fraction of lenticular fragments of the hard phase in 75% reduction. The tensile results demonstrated the fracture phenomenon had a deleterious effect on the strength of laminated plate. Finite element (FEM) analysis of deformation of aluminum composites was carried in order to gain insight into the interface evolution during cold rolling process. It is argued that plastic instabilities were derived from shearing regions with preferential local deformation introduced by the difference in flow properties between the constituent metals.