Aluminum Company of America

Thomas J VanSumeren

Robert P Evert

Blair T Allison

John S Schultz

A process for stretch forming hollow metal bodies, such as aluminum alloy extrusions. The extrusions are stretched longitudinally, bent transversely of the pulling direction, and then subjected to pressure from an incompressible fluid in a hollow interior. In a preferred embodiment, the incompressible fluid is water at a pressure sufficient to deform at least part of the extrusion outwardly of its hollow interior. The incompressible fluid reduces dimensional distortions in the shaped product.

Process for stretch forming hollow metal bodies

A hollow metal body is shaped by a process including simultaneous stretching and bending. The body is stretched longitudinally by pulling end portions in opposite directions with sufficient force to exceed an elastic limit and to initiate elongation through plastic deformation. While the body is being stretched longitudinally, it is bent between its end portions transversely of the direction of pulling. Solid polymeric first and second mandrels are inserted into end portions of the body to prevent collapse during bending.

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Waterford, MI, United States of America

Thomas J VanSumeren