Anisotropic tensile properties of recovery annealed aluminum alloy sheet

Aluminum alloy sheets fabricated by direct chill cast (DC) and continuous cast (CC) routes were investigated. The aluminum sheet produced by heavy cold-rolling and recovery anneal exhibits highly anisotropic tensile properties, especially a rather poor ductility along the direction 45° from the rolling direction. The anisotropic tensile behavior has its origin in the rolling texture. The poor ductility in 45° direction could be attributed to flow localization associated with intense shear banding, which was triggered by the yielding phenomenon in DC specimens. For CC specimens, discontinuous yielding does not occur because of the presence of residual dislocations, and the problem of low ductility in 45° direction is less severe than that in DC specimens. For both DC and CC aluminum sheet, increasing strain rate could enhance the strength and also improve the ductility.