Press-Formability of Stainless Steel and Aluminum Clad Sheet

This paper deals with a stainless steel and aluminum clad sheet produced by pressure welded hot rolled sheets. The tensile tests made on the clad sheet as well as the elements which compose it, stainless steel and aluminum sheets, were carried out in order to determine the fundamental mechanical properties. Basic press-forming tests, which include punch stretching and deep-drawing, were done. The characteristics of the joining process within the range of uniform elongation shows that the aluminum portion has higher ductility than that of stainless steel. However, the latter has higher local deformation and a larger Lankford, r, owing to inherent characteristic of the two materials. The formability in the processes of both stretching and deep-forming, are higher when the aluminum is set on the outer side of the cup. The factors related to the deformation, such as wrinkling and cup height are controlled by the stainless steel portion due to its high strength. The fracture and deformation mechanisms are clarified by the detailed measurements of thickness strain.