Achieving Superplasticity of Al-1%Mg-0.2%Sc Alloy in Plate Samples Processed by Equal-channel Angular Pressing

Abstract

Equal-channel angular pressing (ECAP) was successfully applied to samples of an Al-1% Mg-0.2% Sc alloy in the form of plates. Pressings were conducted at room temperature using route BCZ in which the plates are rotated in the same direction by 90 � around the vertical axis between each pass. Following ECAP, the grain size was measured as � 0:5 mm. Tensile specimens were cut from the plates and pulled to failure at a temperature of 673 K. Superplastic elongations were achieved and the measured ductilities were essentially independent of the orientation within the plate. These results provide the first demonstration of the potential for directly producing a plate in a superplastic condition through the application of ECAP. Thus, this new procedure removes the necessity of rolling conventional as-pressed bars or rods into sheets or plates for subsequent superplastic forming operations.