US3862489A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing boron-aluminum composite tubes with integral end fittings
Assignee: General Dynamics Corp
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Filing: 1973-11-29
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Granted: 1975-01-28
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Expires: 1993-11-29
Abstract
Abstract A method of simultaneously forming Boron-Aluminum composite tubes and securely bonding them to aluminum or titanium endfittings. Sheets comprising unidirectional boron fibers bonded to aluminum foil or imbedded in an aluminum matrix are wound into a tubular shape with the fibers substantially parallel to the tube axis or at an angle of up to about 45*. Sheets with one or both ends tapered are rolled to form a number of helical steps, in telescoping fashion, at one end. An end fitting have a corresponding taper is placed in contact with each tapered tube end. This assembly is placed between inner and outer shaping tubes and the space between the shaping tubes is sealed and the space evacuated. The wall strength of the inner shaping tube is lower than that of the outer tube. The assembly is placed in an autoclave, heated to the appropriate diffusion bonding temperature and placed under sufficient isostatic pressure to deform the inner shaping tube outwardly to press the composite tube and fitting against the outer shaping tube. Upon removal of the shaping tubes, a well-consolidated composite tube diffusion bonded to the end fitting results.
Inventors
- 👤 Martin Donald Weisinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:38
CPC Classifications
B; B21; B21C; B21C37/00; B21C37/06; B21C37/15; B21C37/154; F; F16; F16L; F16L9/00; F16L9/02; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4981
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
153 words
A METHOD OF FABRICATING A COMPOSITE STRUCTURE WHICH COMPRISES THE STEPS OF: PROVIDING AT LEAST ONE COMPOSITE SHEET COMPRISING BORON FIBERS IN AN ALUMINIUM MATRIX; FORMING A COIL OF SAID SHEET AROUND A FIRST SHAPING TUBE IN A MANNER PROVIDING A STEPPED, TELESCOPING APPEARANCE TO AT LEAST A FIRST END OF SAID COIL; PLACING A FITTING OVER SAID FIRST TUBE INTO CONTACT WITH SAID FIRST END OF SAID COIL, SAID FITTING BEING SHAPED TO CONFORM TO SAID STEPPED, TELESCOPING, CONFIGURATION; SAID FITTING COMPRISING AN ALLOY SELECTED FROM THE GROUP CONSISTING OF TITANIUM AND ALUMINUM ALLOYS; INSERTING THE ASSEMBLED FIRST FORMING TUBE INTO A SECOND SHAPING TUBE; SEALING THE ASSEMBLY OF TUBES AND SUBSTANTIALLY EVACUATING GASES FROM THEREBETWEEN; SUBJECTING SAID ASSEMBLY TO A DIFFUSION BONDING TEMPERATURE AT AN ISOSTATIC PRESSURE SUFFICIENT TO CONSOLIDATE SAID COIL FOR A PERIOD SUFFICIENT TO DIFFUSION BOND SAID COIL TOGETHER AND TO SAID FITTING; AND REMOVING SAID SHAPING TUBES.
Claim 2
Independent Claim
153 words
A METHOD OF FABRICATING A COMPOSITE STRUCTURE WHICH COMPRISES THE STEPS OF: PROVIDING AT LEAST ONE COMPOSITE SHEET COMPRISING BORON FIBERS IN AN ALUMINIUM MATRIX; FORMING A COIL OF SAID SHEET AROUND A FIRST SHAPING TUBE IN A MANNER PROVIDING A STEPPED, TELESCOPING APPEARANCE TO AT LEAST A FIRST END OF SAID COIL; PLACING A FITTING OVER SAID FIRST TUBE INTO CONTACT WITH SAID FIRST END OF SAID COIL, SAID FITTING BEING SHAPED TO CONFORM TO SAID STEPPED, TELESCOPING, CONFIGURATION; SAID FITTING COMPRISING AN ALLOY SELECTED FROM THE GROUP CONSISTING OF TITANIUM AND ALUMINUM ALLOYS; INSERTING THE ASSEMBLED FIRST FORMING TUBE INTO A SECOND SHAPING TUBE; SEALING THE ASSEMBLY OF TUBES AND SUBSTANTIALLY EVACUATING GASES FROM THEREBETWEEN; SUBJECTING SAID ASSEMBLY TO A DIFFUSION BONDING TEMPERATURE AT AN ISOSTATIC PRESSURE SUFFICIENT TO CONSOLIDATE SAID COIL FOR A PERIOD SUFFICIENT TO DIFFUSION BOND SAID COIL TOGETHER AND TO SAID FITTING; AND REMOVING SAID SHAPING TUBES.
Claim 3
Dependent Claim
51 words
The method according to claim 1 wherein said at least one sheet has a generally rectangular shape with a unidirectional fiber orientation and at least one end is cut diagonally transverse to the fiber direction whereby a smooth, helical telescoping appearance is created when said sheet is coiled about said tube.
Claim 4
Dependent Claim
51 words
The method according to claim 1 wherein said at least one sheet has generally rectangular shape and at least one end is trimmed along lines parallel to that end to provide a plurality of steps, whereby a plurality of discrete steps is created when said sheet is coiled about said tube.
Claim 5
Dependent Claim
46 words
The method according to claim 1 wherein said at least one sheet comprises a plurality of generally rectangular sheets of different lengths in the fiber direction, whereby a plurality of discrete steps is created when said sheets are coiled about said tube in order of length.
Claim 6
Dependent Claim
32 words
The method according to claim 1 wherein said second tube has at least about 1.5 times the wall strength of said first tube whereby said first tube expands during said isostatic pressing.
Claim 7
Dependent Claim
39 words
The method according to claim 1 wherein said assembly is subjected to a temperature of from about 800* to 1000* F and an isostatic pressure of from about 3,000 to 10,000 psi for from about 1 to 3 hours.
Claim 8
Dependent Claim
44 words
The method according to claim 1 wherein said first and second shaping tubes are removed by treating the assembly with a reagent which dissolves the composition of said first and second tubes without significantly affecting the composition of said composite sheets or said fitting.
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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) | 1978-01-27 | 1978-07-29 | 1979-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-27 | 1982-07-29 | 1983-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-27 | 1986-07-29 | 1987-01-28 | $7700.00 | Window Closed / Lapsed |