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US4353780A
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Chemical milling of high tungsten content superalloys
Assignee: RTX Corp
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Filing: 1980-10-01
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Granted: 1982-10-12
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Expires: 2000-10-01
Abstract
Abstract Chemical milling of cast superalloys having high tungsten contents is advantageously accomplished with an etchant which consists by volume percent of 40-60 concentrated HNO 3 , 0.6-0.8 concentrated HF, 30-70 H 2 O, with which is included at least 0.008 moles/liter CuSO 4 and 0.0016-0.025 moles/liter FeCl 3 . Preferably the molar ratio of CuSO 4 to FeCl 3 is 2:1 and etching is accomplished in the range 50°-80° C.
Inventors
- 👤 Robert E. Fishter
- 👤 Henry Lada
- 👤 Brian A. Manty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:05
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C23F1/28
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
70 words
The method of chemical milling a superalloy having a base metal selected from the group consisting of nickel and cobalt, and a tungsten content of greater than 6 weight percent, which comprises the use of the etchant consisting essentially by volume percent of 40-60 concentrated HNO 3 , 0.3-0.8 concentrated HF, and 30-70 H 2 O, together with at least 0.008 moles/liter CuSO 4 and 0.0016-0.025 moles/liter FeCl 3 .
Claim 2
Independent Claim
70 words
The method of chemical milling a superalloy having a base metal selected from the group consisting of nickel and cobalt, and a tungsten content of greater than 6 weight percent, which comprises the use of the etchant consisting essentially by volume percent of 40-60 concentrated HNO 3 , 0.3-0.8 concentrated HF, and 30-70 H 2 O, together with at least 0.008 moles/liter CuSO 4 and 0.0016-0.025 moles/liter FeCl 3 .
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein CuSO 4 is less than 0.083 moles/liter.
Claim 4
Dependent Claim
42 words
The method of claim 1 wherein the etchant has the composition consisting essentially by volume of about 50 percent HNO 3 , 0.3 percent HF, and 50 percent H 2 O, with 0.008 moles/liter CuSO 4 and 0.004 moles/liter FeCl 3 .
Claim 5
Independent Claim
20 words
The method of claims 1 or 2 wherein the molar proportion of CuSO 4 and FeCl 3 is about 2:1.
Claim 6
Dependent Claim
24 words
The method of claim 1 wherein the superalloy composition consists essentially by weight percent of 10Co, 9Cr, 2Ti, 5Al, 12W, 1Cb, 0.15C, 0.01B, 0.05Zr.
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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) | 1985-10-11 | 1986-04-12 | 1986-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-11 | 1990-04-12 | 1990-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-11 | 1994-04-12 | 1994-10-12 | $7700.00 | Window Closed / Lapsed |