Superplastic microforming of Mg–9Al–1Zn alloy with ultrafine-grained microstructure

Submicron grain size Mg–9Al–1Zn magnesium alloy was processed by severe plastic deformation through differential speed rolling (HRDSR), and exhibited excellent superplasticity and microformability at relatively low-temperatures. Beside the grain size, transition from superplastic flow to non-superplastic flow during microforming was proposed to be an important parameter greatly affecting the microformability. Under optimum forming conditions, the microformed components retained the fine grain size of the HRDSRed Mg alloy.