F. K. Abu-Farha, University of Kentucky, Lexington, KY; M. A. Nazzal, German Jordanian University, Amman, Jordan; M. K. Khraisheh, Masdar Institute of Science and Technology, Abu Dhabi, United Arab Emirates
The superplastic forming technique (SPF) is a unique sheet metal forming process that stretches the limits of formability in lightweight alloys beyond conventional, promising greater potentials for applications in the transportation industry. The technique, primarily practiced by pneumatic bulge forming, offers great advantages over conventional forming operations. The ability to shape hard-to-form alloys into highly intricate shapes remains one of the most attractive. Yet, this is generally achieved at low forming rates, causing a major limitation in SPF’s industrial use on a larger scale. In order to overcome this drawback, superplastic forming can be merged or hybridized with several other manufacturing processes, for enhanced forming efficiency and improved productivity merits.
This work presents one of such hybrid concepts, in which the pneumatic bulge forming practice of superplastic forming is combined with the conventional mechanical deep drawing operation. Sheets are partially formed by a fast deep drawing step, followed by a finishing pneumatic bulge forming step that takes care of the intricate details of the shapes to be formed. Forming according to this concept is first FE-simulated, before being carried out at elevated temperatures, using AZ31 magnesium alloy sheets. Both the FE and experimental results demonstrate how forming time can be considerably reduced, while sustaining the formability merits associated with the superplastic forming process
Summary: This work presents a hybrid concept in which the pneumatic bulge forming practice of superplastic forming is combined with the conventional mechanical deep drawing operation.
