Patent ID: 7389665

Claim:
A process for forming a workpiece comprising the steps of: heating the workpiece to a superplastic forming temperature; providing a draw die having and upper die member and a lower die member, at least one of said die members including a punch and the opposite die member having a die cavity, the draw die further including a blank holder; placing the heated workpiece in the draw die between the upper and lower die members and forming a preform by drawing at least a portion of the workpiece into the die cavity wherein the preform includes a cup portion and a flange portion; using the draw die to distribute the material of the workpiece and create the preform in a preconfigured shape; providing a superplastic forming tool having an upper die member and a lower die member with one of said upper die member and said lower die member having a mold cavity including a mold surface; removing the preform from the draw die and placing the preform in the superplastic forming tool such that the can portion of the preform is located in the mold cavity of the lower die member of the superplastic forming tool; closing the superplastic forming tool by bringing the upper die member and lower die member into contact with the preform whereby the preform is sandwiched between the upper die member and lower die member thereby creating a seal about the peripheral edge of the preform; applying gas pressure to one side of the preform to drive the workpiece against the mold surface of the mold cavity to complete the forming process.