Effect of heat treatment on tensile deformation characteristics and properties of Al3003/STS439 clad composite

The tensile deformation and fracture behaviors of roll-bonded Al3003/STS439 clad composite were studied. The mutual constraint and interaction of joined Al and STS with different deformation characteristics tend to shape the deformed specimen geometry to appear similar and induce the simultaneous fracture of Al and STS. The examination of the fractured clad revealed more uniform deformation of less ductile metal layer was induced by co-deforming more ductile metal layer in the clad composite, enhancing the overall tensile ductility. The suppression of neck formation in STS layer of Al3003/STS439 clad composite was observed to be induced by the resistance to neck formation of joined Al layer, rendering the enhanced ductility of joined STS layer over the separated STS layer. Excellent interface bonding and absence of brittle intermetallics at the interface are prerequisites for the enhanced ductility of clad composites because constraint by the adjacent joined metal layer can be made by the stress and strain transfer through the interface. The strength of the roll-bonded Al3003/STS439 clad composite is in close agreement with that calculated from the rule of mixture.