Method for superplastic forming by internal pressure

Claim 1

A method for superplastically forming a part from a blank of material, comprising the steps of: a) providing a blank workpiece of superplastic material which exhibits an effective value of strain rate sensitivity at a forming temperature; b) providing a first die having a forming surface which is complementary to the shape of said part; c) providing a second die capable of offering a sealed space therein with said blank workpiece; d) positioning said blank workpiece between said first die opposite said forming surface and said second die; e) placing a high gas pressure material capable of producing 50-300 psi gas pressure at said forming temperature between said blank workpiece and said second die; f) clamping said dies and said blank workpiece to make said space sealed; g) heating said blank workpiece at said forming temperature so that said high gas pressure material can produce high pressure gas and applies positive pressure to push said blank workpiece to said forming surface to form a superplastic part; and h) maintaining said positive pressure and said forming temperature for a time duration sufficient to produce the part.

Claim 2

A method for superplastically forming a part from a blank of material, comprising the steps of: a) providing a blank workpiece of superplastic material which exhibits an effective value of strain rate sensitivity at a forming temperature; b) providing a first die having a forming surface which is complementary to the shape of said part; c) providing a second die capable of offering a sealed space therein with said blank workpiece; d) positioning said blank workpiece between said first die opposite said forming surface and said second die; e) placing a high gas pressure material capable of producing 50-300 psi gas pressure at said forming temperature between said blank workpiece and said second die; f) clamping said dies and said blank workpiece to make said space sealed; g) heating said blank workpiece at said forming temperature so that said high gas pressure material can produce high pressure gas and applies positive pressure to push said blank workpiece to said forming surface to form a superplastic part; and h) maintaining said positive pressure and said forming temperature for a time duration sufficient to produce the part.

Claim 5

A method for superplastic forming a metallic structure from a plurality of workpieces, comprising the steps of: a) providing a blank workpiece of superplastic material which exhibits an effective value of strain rate sensitivity at a forming temperature; b) providing a first die having a forming surface which is complementary to the shape of said part; c) providing at least one metal workpiece to be diffusion bonded to said blank workpiece; d) providing a second die capable of offering a sealed space therein with said blank workpiece in said first die; e) positioning said blank workpiece between said first die opposite said forming surface and said second die; f) placing a high gas pressure material capable of producing 50-300 psi gas pressure at said forming temperature between said blank workpiece and said second die; g) clamping said dies and said blank workpiece to make said space sealed; h) heating said blank workpiece at said forming temperature sufficient to produce diffusion bonding of said blank workpiece to said at least one metal workpiece so that said high gas pressure material can produce high pressure gas and applies positive pressure to push said blank workpiece to said forming surface and concurrent with diffusion bonding to form a superplastic part; and i) maintaining said positive pressure and said forming temperature for a time duration sufficient to produce the metallic structure.

Claim 6

A method for superplastic forming a metallic structure from a plurality of workpieces, comprising the steps of: a) providing a blank workpiece of superplastic material which exhibits an effective value of strain rate sensitivity at a forming temperature; b) providing a first die having a forming surface which is complementary to the shape of said part; c) providing at least one metal workpiece to be diffusion bonded to said blank workpiece; d) providing a second die capable of offering a sealed space therein with said blank workpiece in said first die; e) positioning said blank workpiece between said first die opposite said forming surface and said second die; f) placing a high gas pressure material capable of producing 50-300 psi gas pressure at said forming temperature between said blank workpiece and said second die; g) clamping said dies and said blank workpiece to make said space sealed; h) heating said blank workpiece at said forming temperature sufficient to produce diffusion bonding of said blank workpiece to said at least one metal workpiece so that said high gas pressure material can produce high pressure gas and applies positive pressure to push said blank workpiece to said forming surface and concurrent with diffusion bonding to form a superplastic part; and i) maintaining said positive pressure and said forming temperature for a time duration sufficient to produce the metallic structure.

Claim 8

A method for superplastic forming a hollow part by internal pressure, comprising the steps of: b) providing two disk blank workpieces of superplastic material which exhibit an effective value of strain rate sensitivity at a forming temperature; c) providing a metal ring workpiece to be diffusion bonded to said two disk blank workpieces, said metal ring work pieces has a hole formed thereon; d) sandwiching said metal ring workpiece between said two disk blank workpieces and heating at a temperature sufficient to produce diffusion bonding of said two disc blank work pieces to said metal ring workpiece for a time period sufficient to form a hollow cylindrical body; e) placing a high gas pressure material capable of producing 50-300 psi gas pressure at said forming temperature in said hollow cylindrical body through said hole and sealing said hole; f) heating said hollow cylindrical body at said forming temperature to enable said high gas pressure material to produce gas to apply positive internal pressure to said disk blank work pieces of said hollow cylindrical body to form the hollow part.

Claim 9

A method for superplastic forming a hollow part by internal pressure, comprising the steps of: b) providing two disk blank workpieces of superplastic material which exhibit an effective value of strain rate sensitivity at a forming temperature; c) providing a metal ring workpiece to be diffusion bonded to said two disk blank workpieces, said metal ring work pieces has a hole formed thereon; d) sandwiching said metal ring workpiece between said two disk blank workpieces and heating at a temperature sufficient to produce diffusion bonding of said two disc blank work pieces to said metal ring workpiece for a time period sufficient to form a hollow cylindrical body; e) placing a high gas pressure material capable of producing 50-300 psi gas pressure at said forming temperature in said hollow cylindrical body through said hole and sealing said hole; f) heating said hollow cylindrical body at said forming temperature to enable said high gas pressure material to produce gas to apply positive internal pressure to said disk blank work pieces of said hollow cylindrical body to form the hollow part.