US3920175A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for superplastic forming of metals with concurrent diffusion bonding
Assignee: Boeing North American Inc
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Filing: 1974-10-03
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Granted: 1975-11-18
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Expires: 1994-10-03
Abstract
Abstract A method for fabrication of metal structures, especially those with a complex variable thickness form, in which a metal such as a titanium alloy blank is superplastically formed and concurrently diffusion bonded to other metal workpieces to form a desired structure. The metal blank, at least one shaping member, and at least one metal workpiece to be bonded to the metal blank are located within an enclosure. The metal blank and metal workpieces are heated to a suitable forming and bonding temperature and the metal blank stretched substantially in excess of the original surface area under a fluid pressure loading causing it to deform against the shaping member and intimately contact the other metal workpieces for diffusion bonding. An inert gas and/or vacuum environment can be provided in the enclosed area to prevent contamination by air at the elevated temperatures employed.
Inventors
- 👤 Charles Howard Hamilton
- 👤 Jr Leonard A Ascani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:37
CPC Classifications
B; B21; B21D; B21D26/00; B21D26/02; B21D26/053; B21D26/055; B23; B23K; B23K20/00; B23P; B23P15/00; B23P15/26; B30; B30B; B30B5/00; B30B5/02
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
179 words
A method of making a metallic structure from a plurality of workpieces comprising: providing at least one shaping member; providing a metal blank workpiece having an effective strain rate sensitivity and two opposed principal surfaces; providing at least one metal workpiece to be bonded to said metal blank; enclosing an area around said metal blank, said at least one shaping member, and said at least one metal workpiece; heating said metal blank and said at least one metal workpiece to a temperature suitable for forming said metal blank and sufficient to produce bonding of said metal blank to said at least one metal workpiece under coordinated temperaturepressure-time duration conditions; inducing tensile stress in said metal blank by applying a pressure loading across said principal surfaces thereof, causing said metal blank to deform against, and into intimate contact with said at least one shaping member and said at least one metal workpiece; and maintaining said pressure loading and said temperature for a time duration sufficient to produce bonding between said metal blank workpiece and said at least one metal workpiece.
Claim 2
Independent Claim
179 words
A method of making a metallic structure from a plurality of workpieces comprising: providing at least one shaping member; providing a metal blank workpiece having an effective strain rate sensitivity and two opposed principal surfaces; providing at least one metal workpiece to be bonded to said metal blank; enclosing an area around said metal blank, said at least one shaping member, and said at least one metal workpiece; heating said metal blank and said at least one metal workpiece to a temperature suitable for forming said metal blank and sufficient to produce bonding of said metal blank to said at least one metal workpiece under coordinated temperaturepressure-time duration conditions; inducing tensile stress in said metal blank by applying a pressure loading across said principal surfaces thereof, causing said metal blank to deform against, and into intimate contact with said at least one shaping member and said at least one metal workpiece; and maintaining said pressure loading and said temperature for a time duration sufficient to produce bonding between said metal blank workpiece and said at least one metal workpiece.
Claim 3
Independent Claim
198 words
A method of making a metallic structure in a controlled environment from a plurality of workpieces comprising: providing at least one shaping member; providing a metal blank workpiece having an effective strain rate sensitivity and two opposed principal surfaces; providing at least one metal workpiece to be diffusion bonded to said metal blank; enclosing an area around said metal blank, said at least one shaping member, and said at least one metal workpiece; providing an inert gas environment in said enclosed area; heating said metal blank and said at least one metal workpiece to a temperature suitable for superplastic forming said metal blank and sufficient to produce diffusion bonding of said metal blank to said at least one metal workpiece under coordinated temperature-pressure-time duration conditions; inducing tensile stress in said metal blank by applying a fluid pressure loading across said principal surfaces thereof, causing said metal blank to deform against and into intimate contact with said at least one shaping member and said at least one metal workpiece; and maintaining said fluid pressure loading and said temperature for a time duration sufficient to produce diffusion bonding between said metal blank workpiece and said at least one metal workpiece.
Claim 4
Independent Claim
198 words
A method of making a metallic structure in a controlled environment from a plurality of workpieces comprising: providing at least one shaping member; providing a metal blank workpiece having an effective strain rate sensitivity and two opposed principal surfaces; providing at least one metal workpiece to be diffusion bonded to said metal blank; enclosing an area around said metal blank, said at least one shaping member, and said at least one metal workpiece; providing an inert gas environment in said enclosed area; heating said metal blank and said at least one metal workpiece to a temperature suitable for superplastic forming said metal blank and sufficient to produce diffusion bonding of said metal blank to said at least one metal workpiece under coordinated temperature-pressure-time duration conditions; inducing tensile stress in said metal blank by applying a fluid pressure loading across said principal surfaces thereof, causing said metal blank to deform against and into intimate contact with said at least one shaping member and said at least one metal workpiece; and maintaining said fluid pressure loading and said temperature for a time duration sufficient to produce diffusion bonding between said metal blank workpiece and said at least one metal workpiece.
Claim 5
Dependent Claim
41 words
The method as defined in claim 2 also including locating said metal blank with respect to said shaping member by positioning said metal blanK with its principal opposed surfaces in operative projection with respect to said at least one shaping member.
Claim 6
Dependent Claim
45 words
The method as defined in claim 3 wherein said fluid pressure loading across said principal surfaces is applied for a substantial period of time inversely related to the induced tensile stress and said metal blank is stretched substantially in excess of its original surface area.
Claim 7
Dependent Claim
42 words
A method as defined in claim 4 wherein said enclosed area is divided into first and second chambers by said metal blank, and said at least one shaping member and said at least one metal workpiece are located in said first chamber.
Claim 8
Dependent Claim
55 words
The method as defined in claim 5 wherein said fluid pressure loading comprises a greater pressure of inert gas in said second chamber relative to said first chamber and said first chamber is vented to allow for efflux of inert gas as said metal blank deforms and thereby reduces the size of said first chamber.
Claim 9
Dependent Claim
32 words
The method as defined in claim 5 wherein said fluid pressure loading comprises application of vacuum to said first chamber while maintaining a constant pressure of inert gas in said second chamber.
Claim 10
Dependent Claim
30 words
The method as defined in claim 5 wherein said fluid pressure loading comprises application of vacuum to said first chamber and increased pressure of inert gas in said second chamber.
Claim 11
Dependent Claim
28 words
The method of claim 5 wherein said inert gas is argon, said metal blank is titanium alloy sheet, and said at least one metal workpiece is titanium alloy.
Claim 12
Dependent Claim
22 words
The method as defined in claim 5 also including sealing said enclosed area to prevent influx of air into said enclosed area.
Claim 13
Dependent Claim
18 words
The method as defined in claim 5 wherein said at least one shaping member is a female die.
Claim 14
Dependent Claim
25 words
The method as set out in claim 5 wherein said at least one shaping member comprises a female die and at least one male die.
Claim 15
Dependent Claim
21 words
The method as set out in claim 5 wherein said at least one shaping member is at least one male die.
Claim 16
Dependent Claim
29 words
The method as set out in claim 5 also including positioning said at least one metal workpiece parallel to and in contact with said metal blank prior to forming.
Claim 17
Dependent Claim
28 words
The method as set out in claim 5 also including positioning said at least one metal workpiece normal to and spaced from said metal blank prior to forming.
Claim 18
Dependent Claim
29 words
The method as set out in claim 5 also including positioning said at least one metal workpiece normal to and in contact with said metal blank prior to forming.
Claim 19
Dependent Claim
36 words
The method as set out in claim 5 wherein said first chamber has a wall with at least one groove therein and said at least one metal workpiece is located in said at least one groove.
Claim 20
Dependent Claim
33 words
The method as set out in claim 5 also including after the step of maintaining said fluid pressure loading the additional step of increasing said fluid pressure loading to insure complete diffusion bonding.
Claim 21
Independent Claim
291 words
A method of making a metallic structure from a plurality of workpieces comprising: providing at least two shaping members; providing two metal blank workpieces having an effective strain rate sensitivity and each having two opposed principal surfaces, said metal blanks being positioned parallel to and in contact with each other and with a principal surface of one metal blank overlying a principal surface of the other metal blank; providing at least one metal workpiece to be bonded to at least one of said metal blanks; enclosing an area around said metal blanks said at least two shaping members, and said at least one metal workpiece; effectively constraining a periphery of each of said metal blanks by application of pressure, circumscribing a surface portion of each of said metal blanks; heating said metal blanks and said at least one metal workpiece to a temperature suitable for forming said metal blanks and sufficient to produce bonding of said constrained peripheries of said metal blanks to one another and bonding of at least one of said metal blanks to said at least one metal workpiece under coordinateD temperature-pressure-time duration conditions; inducing tensile stress in the circumscribed portions of said metal blanks by applying a fluid pressure loading across said principal surfaces thereof, causing the circumscribed portions of said metal blanks to deform in approximately opposite directions, against, and into intimate contact with, said at least two shaping members and the circumscribed portion of at least one of said metal blanks against, and into intimate contact with, said at least one metal workpiece; and maintaining said fluid pressure loading and said temperature for a time duration sufficient to produce bonding between said at least one metal blank workpiece and said at least one metal workpiece.
Claim 22
Independent Claim
291 words
A method of making a metallic structure from a plurality of workpieces comprising: providing at least two shaping members; providing two metal blank workpieces having an effective strain rate sensitivity and each having two opposed principal surfaces, said metal blanks being positioned parallel to and in contact with each other and with a principal surface of one metal blank overlying a principal surface of the other metal blank; providing at least one metal workpiece to be bonded to at least one of said metal blanks; enclosing an area around said metal blanks said at least two shaping members, and said at least one metal workpiece; effectively constraining a periphery of each of said metal blanks by application of pressure, circumscribing a surface portion of each of said metal blanks; heating said metal blanks and said at least one metal workpiece to a temperature suitable for forming said metal blanks and sufficient to produce bonding of said constrained peripheries of said metal blanks to one another and bonding of at least one of said metal blanks to said at least one metal workpiece under coordinateD temperature-pressure-time duration conditions; inducing tensile stress in the circumscribed portions of said metal blanks by applying a fluid pressure loading across said principal surfaces thereof, causing the circumscribed portions of said metal blanks to deform in approximately opposite directions, against, and into intimate contact with, said at least two shaping members and the circumscribed portion of at least one of said metal blanks against, and into intimate contact with, said at least one metal workpiece; and maintaining said fluid pressure loading and said temperature for a time duration sufficient to produce bonding between said at least one metal blank workpiece and said at least one metal workpiece.
Claim 23
Independent Claim
220 words
A method of making metallic structures from a plurality of workpieces comprising: providing at least two shaping members; providing two metal blank workpieces having an effective strain rate sensitivity and each having two opposed principal surfaces, said metal blanks being positioned in spaced relationship to one another; providing at least one metal workpiece to be bonded to at least one of said metal blanks; enclosing an area around said metal blanks, said at least two shaping members, and said at least one metal workpiece; heating said metal blanks and said at least one metal workpiece to a temperature suitable for forming said metal blanks and sufficient to produce bonding of at least one of said metal blanks to said at least one metal workpiece under coordinated temperature-pressure-time duration conditions; inducing tensile stress in said metal blanks by applying a fluid pressure loading across said principal surfaces thereof, causing said metal blanks to deform in approximately opposite directions, against, and into intimate contact with said at least two shaping members, and at least one of said metal blanks against, and into contact with, said at least one metal workpiece; and maintaining said fluid pressure loading and said temperature for a time duration sufficient to produce bonding between said at least one metal blank workpiece and said at least one metal workpiece.
Claim 24
Independent Claim
220 words
A method of making metallic structures from a plurality of workpieces comprising: providing at least two shaping members; providing two metal blank workpieces having an effective strain rate sensitivity and each having two opposed principal surfaces, said metal blanks being positioned in spaced relationship to one another; providing at least one metal workpiece to be bonded to at least one of said metal blanks; enclosing an area around said metal blanks, said at least two shaping members, and said at least one metal workpiece; heating said metal blanks and said at least one metal workpiece to a temperature suitable for forming said metal blanks and sufficient to produce bonding of at least one of said metal blanks to said at least one metal workpiece under coordinated temperature-pressure-time duration conditions; inducing tensile stress in said metal blanks by applying a fluid pressure loading across said principal surfaces thereof, causing said metal blanks to deform in approximately opposite directions, against, and into intimate contact with said at least two shaping members, and at least one of said metal blanks against, and into contact with, said at least one metal workpiece; and maintaining said fluid pressure loading and said temperature for a time duration sufficient to produce bonding between said at least one metal blank workpiece and said at least one metal workpiece.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |