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US4269053A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of superplastic forming using release coatings with different coefficients of friction

Assignee: Boeing North American Inc
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Filing: 1979-07-25
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Granted: 1981-05-26
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Expires: 1999-07-25
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Abstract

Abstract An improvement to the method of making a structure by superplastic forming, wherein portions of a preform are expanded, in the superplastic condition, against a forming member, is disclosed. The improvement comprises the step, prior to expanding the preform, of providing a lower coefficient of friction between the portions of the preform to be expanded and the forming member than which exists between the portions of the preform where expansion is intended to be minimal and the forming member. The two values of coefficient of friction are obtained by applying first and second release coatings to the portions of the preform to be expanded and those where expansion is to be minimal respectively, with the first release coating having a coefficient of friction less than the second release coating. Alternately, the first and second release coatings can be applied to the forming member. The preferred first and second release coatings are boron nitride and yttria respectively.

Inventors

  • 👤 Suphal P. Agrawal
  • 👤 Edward D. Weisert

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 17:20
CPC Classifications
B; B21; B21D; B21D26/00; B21D26/02; B21D26/053; B21D26/055

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 84 words
In the method of making a structure by superplastic forming, wherein portions of a preform, are expanded in a superplastic condition against a forming member, the improvement comprising the step, prior to expanding said preform, of applying a material between said preform and said forming member that provides a lower coefficient of friction between said portions of said preform to be expanded and said forming member than exists between said portions of said preform where expansion is to be minimal and said forming member.
Claim 2
Dependent Claim 84 words
In the method of making a structure by superplastic forming, wherein portions of a preform, are expanded in a superplastic condition against a forming member, the improvement comprising the step, prior to expanding said preform, of applying a material between said preform and said forming member that provides a lower coefficient of friction between said portions of said preform to be expanded and said forming member than exists between said portions of said preform where expansion is to be minimal and said forming member.
Claim 3
Dependent Claim 58 words
The method of claim 1 wherein said material is applied by: applying a first release coating on said portions of said preform to be expanded; and applying a second release coating on said portions of said preform where expansion is to be minimal, said first release coating having a coefficient of friction less than said second release coating.
Claim 4
Dependent Claim 73 words
The method of claim 2 wherein said material is applied is by: applying a first release coating to said forming member in position to contact said portions of said preform to be expanded; and applying a second release coating to said forming member in positions to contact said portions of said preform where expansion is to be minimal; said first release coating having a coefficient of friction less than said second release coating.
Claim 5
Dependent Claim 12 words
The method of claim 1 wherein said preform is a titanium alloy.
Claim 6
Dependent Claim 15 words
The method of claim 2 of 3 wherein said first release coating is boron nitride.
Claim 7
Dependent Claim 14 words
The method of claim 2 or 4 wherein said second release coating is yttria.
Claim 8
Dependent Claim 58 words
In forming of metals wherein portions of a preform are applied against a forming member, the process comprising applying between said preform and said forming member a plurality of coatings having differing coefficients of friction, said coatings being applied, respectively, at different locations between said preform and said forming member, such that forming of the preform is uniform.
Claim 9
Dependent Claim 58 words
In forming of metals wherein portions of a preform are applied against a forming member, the process comprising applying between said preform and said forming member a plurality of coatings having differing coefficients of friction, said coatings being applied, respectively, at different locations between said preform and said forming member, such that forming of the preform is uniform.
Claim 10
Dependent Claim 55 words
The process as set forth in claim 7 wherein said plurality of coating a first coating applied to said portions of the preform to be formed; and a second coating applied to said portions of said preform where forming is to be minimized, said first coating having a coefficient friction less than said second coating.
Claim 11
Dependent Claim 19 words
The process as set forth in claim 7 wherein said plurality of coatings are applied to said forming member.
Claim 12
Dependent Claim 69 words
The process as set forth in claim 9 wherein said coatings comprise: a first coating applied to said forming member in positions to contact said portions of said preform to be formed; and a second coating applied to said forming member in positions to contact the portions of said preform where forming is to be minimal said first coating having a coefficient of friction less than said second coating.
Claim 13
Dependent Claim 17 words
The process as set forth in claim 7 wherein said preform is a metal having superplastic characteristics.
Claim 14
Dependent Claim 14 words
The process as set forth in claim 11 wherein said forming is superplastic forming.
Claim 15
Dependent Claim 13 words
The process as set forth in claim 11 wherein said preform is titanium.
Claim 16
Dependent Claim 17 words
The process as set forth in claims 9 or 11 wherein said first coating is boron nitride.
Claim 17
Dependent Claim 16 words
The process as set forth in claim 9 or 11 wherein said second coating is yttria.

References Cited (Backward Citations)

US3655349A Cited
US3934441A Cited
US3979815A Cited
US3927817A Cited
US4096076A Cited
US4055975A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-05-25 1984-11-24 1985-05-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-05-25 1988-11-24 1989-05-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-05-25 1992-11-24 1993-05-26 $7700.00 Window Closed / Lapsed

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