초록 ▼

A method for forming a hollow structure having a predetermined shape from a sheet of superplastic material. The sheet is initially formed into a preform configuration. A reusable fluid inlet tube is placed in the preform configuration to define a port in fluid communication with the interior portion

A method for forming a hollow structure having a predetermined shape from a sheet of superplastic material. The sheet is initially formed into a preform configuration. A reusable fluid inlet tube is placed in the preform configuration to define a port in fluid communication with the interior portion of the preform configuration. The preform configuration is disposed in a containment die, which defines a cavity having the predetermined desired shape. Force is applied to the containment die to temporarily seal the edges of the preform configuration without the use of welding or diffusion bonding. Once its edges are sealed, the preform configuration becomes a gas-tight envelope capable of holding fluid that is introduced through the fluid inlet tube. Fluid (e.g., argon) is fed through the tube to apply internal pressure to the gas-tight preform configuration under superplastic conditions (including appropriate heating) while it is still being held in the containment die so that it superplastically expands in the die cavity (deforms) into a hollow structure having the predetermined shape. The hollow structure may be an aeronautical member, e.g., an airfoil, or a member used in automobiles, furniture, boats, buildings, railroad cars, hospital equipment, architectural panels, or any other application requiring a closed metal shape.

대표청구항 ▼

[ What is claimed is:] [1.] A method for forming a hollow structure having a continuous first edge and a predetermined shape from a sheet capable of being formed under superplastic conditions into the predetermined shape, said method comprising the steps of:(a) forming the sheet into a preform confi

[ What is claimed is:] [1.] A method for forming a hollow structure having a continuous first edge and a predetermined shape from a sheet capable of being formed under superplastic conditions into the predetermined shape, said method comprising the steps of:(a) forming the sheet into a preform configuration having a continuous first edge, an upper face, and a lower face, said upper and lower faces each having an open edge portion;(b) disposing the preform configuration in a containment die comprising a first section and a second section that together define a first cavity having substantially the predetermined shape;(c) applying closing force to the two sections of the containment die to force the two die sections together to trap the edge portions of the preform configuration therebetween and hold the edge portions tightly against each other to temporarily seal those edge portions together to make the preform configuration substantially gas-tight, which substantially gas-tight preform configuration constitutes a packet assembly having an inside and an outside; and(d) increasing the pressure inside the packet assembly with respect to the pressure outside the packet assembly under superplastic forming conditions so that at least some portion of the packet assembly superplastically expands to conform to the first cavity of the containment die and thereby forms a hollow structure having the predetermined shape.