Abstract: This invention defines an improved method for superplastic forming (SPF) of metallic parts in which a cutout is formed in the blank from which the parts will be formed, and a secondary sheet is located between the blank and the pressurized gas. The cutout area of the blank becomes stretched so that there is minimal thinning in the air near the periphery of the cutout(s) in the blank, the secondary sheet is required to carry the gas pressure and to form the parts.

Abstract: A gas management system for delivering forming gas under a controlled pressure through a first portion of a piping network to a region of a forming die between a die lid and a blank to be formed in a superplastic forming machine includes a gas pressure regulator in the piping network and two control loops. The first control loop has a first pressure transducer communicating with the piping network downstream of the gas pressure regulator and operatively with the gas pressure regulator. The second control loop includes a pulse controller downstream of the first pressure transducer and a second pressure transducer communicating with the piping network downstream of the pulse controller and operatively with the pulse controller. The gas pressure regulator receives signals from a controller to adjust the pressure at which the gas pressure regulator opens to release gas through the pressure regulator.