Gm Global Technolgoy Operations, Inc.

Michelle R Goff

Gary A Kruger

Chongmin Kim

Mark G Konopnicki

James Gregory Schroth

Richard Murray Kleber

John Norman Johnson

A method is disclosed for forming sheet metal articles, such as automotive body panels, having significant curvatures in front-to-back and side-to-side directions. Opposing, complementary, preforming and final shape forming tools are used in a single press. A sheet of superplastically or quick plastically formable sheet metal alloy, heated to a forming temperature, is first stretched against the preform tool by the final shape tool to form a preform that has experienced most of the metal stretching required for the final part shape. The preform is removed from the preform tool and formed against the opposing, final shape tool with pressurized gas to obtain the final sheet metal part shape.

Method for stretch forming sheet metal by pressing and the application of gas pressure

A method is disclosed for forming sheet metal articles, such as automotive body panels, having significant curvatures in front-to-back and side-to-side directions. Opposing, complementary, preforming and final shape forming tools are used in a single press. A sheet of superplastically or quick plastically formable sheet metal alloy, heated to a forming temperature, is first stretched against the preform tool using pressurized gas to form a preform that has experienced most of the metal stretching required for the final part shape. The preform is removed from the preform tool and formed against the opposing tool with pressurized gas to obtain the final sheet metal part shape.

Method for double action gas pressure forming sheet material

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Grand Blanc, MI, United States of America

Michelle R Goff