US Patent 7228629 Method of spin forming an automotive wheel rim

The present invention is directed to a method of manufacturing a three piece aluminum wheel assembly comprising the steps of providing a pair of circular blanks made of a heat treatable alloy to be formed into preforms of a general shape. The preforms are subjected to a quenching step in an unconstrained condition to allow for natural thermal deformation during the quenching operation. The as quenched preforms are then subjected to a first forming operation using spin forming to remove the effects of the thermal deformation in the preform, followed by a second forming step using spin forming to shape the component to its desired final shape. The components are then exposed to precipitation heating and finishing to yield the final product.