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Deep drawing experiments using rectangular pans, made of aluminum alloys, have been conducted at the Engineering Research Center for Net Shape Manufacturing (ERC/NSM) at the Ohio State University. A 160 ton Minster hydraulic press was used for the experiments. A 3-D finite element code called PAM-STAMP was used in the simulations. The current study investigates the effect of blank holder force control and blank shape on the final product quality. In the hydraulic press, it was possible to control the blank holding force (BHF) as a function of time. By conducting experiments and simulations using three blank shapes and various BHF profiles, it has been shown that blank shape and the BHF have significant effect on the formability of aluminum alloy pans, and they must be optimized to eliminate wrinkling and fracture. A decreasing BHF profile was shown to be effective in improving part quality and practical for use in industrial applications.

With the availability of advanced machine designs and controls, tube hydroforming has become an economic alternative to various stamping processes. The technology is relatively new so that there is no large “knowledge base” to assist the product and process designers. This paper reviews the fundamentals of tube hydroforming technology and discusses how various parameters, such as tube material properties, pre-form geometry, lubrication and process control affect product design and quality. In addition, relations between process variables and achievable part geometry are discussed. Finally, using examples, the status of the current technology and critical issues for future development are reviewed.