Patent US5248386A successfully refreshed from Google Patents.
US5248386A
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Milling solution and method
Assignee: Alcoa Corp
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Filing: 1992-03-10
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Granted: 1993-09-28
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Expires: 2012-03-10
Abstract
Abstract A substantially nitrate-free solution for milling products of refractory metals, especially titanium, which milling solution comprises: (a) about 20-100 g/l hydrofluoric acid; (b) a hydrogen inhibitor selected from the group comprising of: about 55-650 g/l of sodium chlorate, about 180-650 g/l of ammonium peroxysulfate, and at least about 10 g/l of hydrogen peroxide; and (c) a balance of water and impurities. A method for chemically milling, etching and/or pickling metal products, such as titanium alloy forgings, with the aforementioned solution is also disclosed.
Inventors
- 👤 LeRoy E. Dastolfo, Jr.
- 👤 Gary P. Tarcy
- 👤 William P. Wehrle
- 👤 Mark E. Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 16:47
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C23F1/26; C23F1/02; C23F1/04; C23G; C23G1/00; C23G1/02; C23G1/10; C23G1/106
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
49 words
A substantially nitrate-free solution suitable for milling a metal product at one or more temperatures between about 16°-71° C. (60°-160° F.), which comprises: (a) between about 20-100 g/l of hydrofluoric acid; (b) greater than about 50 g/l of a water-soluble chlorate; and (c) a balance of water and impurities.
Claim 2
Dependent Claim
49 words
A substantially nitrate-free solution suitable for milling a metal product at one or more temperatures between about 16°-71° C. (60°-160° F.), which comprises: (a) between about 20-100 g/l of hydrofluoric acid; (b) greater than about 50 g/l of a water-soluble chlorate; and (c) a balance of water and impurities.
Claim 3
Dependent Claim
19 words
The milling solution of claim 1 which contains about 55-650 g/l of sodium chlorate, potassium chlorate or ammonium perchlorate.
Claim 4
Dependent Claim
22 words
The milling solution of claim 1 which comprises about 35-90 g/l of hydrofluoric acid, about 60-200 g/l of sodium chlorate, and water.
Claim 5
Dependent Claim
31 words
The milling solution of claim 1 wherein the metal product consists essentially of a titanium alloy having at least one of the following: an alpha phase, beta phase and gamma phase.
Claim 6
Dependent Claim
23 words
The milling solution of claim 4 wherein the alloy is selected from the group consisting of: Ti-6Al-4V, Ti-6Al-6V-2Sn, Ti-10V-2Fe-3Al and commercially pure titanium.
Claim 7
Dependent Claim
49 words
A substantially nitrate-free solution suitable for milling a titanium product at one or more temperatures between about 16°-71° C. (60°-160° F.), said solution consisting essentially of: about 20-100 g/l of hydrofluoric acid; at least about 180 g/l of a peroxysulfate ion-containing solution; and a balance of water and impurities.
Claim 8
Dependent Claim
49 words
A substantially nitrate-free solution suitable for milling a titanium product at one or more temperatures between about 16°-71° C. (60°-160° F.), said solution consisting essentially of: about 20-100 g/l of hydrofluoric acid; at least about 180 g/l of a peroxysulfate ion-containing solution; and a balance of water and impurities.
Claim 9
Dependent Claim
19 words
The solution of claim 6 wherein the bath is heated to about 21°-57° C. (70°-135° F.) for milling purposes.
Claim 10
Dependent Claim
18 words
The solution of claim 6 which contains about 200-450 g/l of ammonium peroxysulfate, potassium peroxysulfate or sodium peroxysulfate.
Claim 11
Dependent Claim
13 words
The solution of claim 6 wherein the titanium product is a Ti-6Al-4V forging.
Claim 12
Dependent Claim
22 words
The solution of claim 6 wherein titanium is removed from the product surface at a rate of about 0.15 mils/side/minute or higher.
Claim 13
Dependent Claim
17 words
The solution of claim 6 which produces a post-milling hydrogen content of about 150 ppm or less.
Claim 14
Dependent Claim
49 words
A substantially nitrate-free solution suitable for milling a metal product at one or more temperatures between about 16°-71° C. (60°-160° F.), which comprises: (a) between about 20-100 g/l of hydrofluoric acid; (b) at least about 10 g/l of a peroxide compound; and (c) a balance of water and impurities.
Claim 15
Dependent Claim
49 words
A substantially nitrate-free solution suitable for milling a metal product at one or more temperatures between about 16°-71° C. (60°-160° F.), which comprises: (a) between about 20-100 g/l of hydrofluoric acid; (b) at least about 10 g/l of a peroxide compound; and (c) a balance of water and impurities.
Claim 16
Dependent Claim
14 words
The milling solution of claim 12 which contains about 20-150 g/l of hydrogen peroxide.
Claim 17
Dependent Claim
31 words
The milling solution of claim 12 wherein the metal product consists essentially of a titanium alloy having at least one of the following: an alpha phase, beta phase and gamma phase.
Claim 18
Dependent Claim
23 words
The milling solution of claim 14 wherein the alloy is selected from the group consisting of: Ti-6Al-4V, Ti-6Al-6V-2Sn, Ti-10V-2Fe-3Al and commercially pure titanium.
Claim 19
Dependent Claim
20 words
The milling solution of claim 12 wherein the bath is heated to about 21°-57° C. (70°-135° F.) for milling purposes.
Claim 20
Dependent Claim
22 words
The solution of claim 12 wherein titanium is removed from the product surface at a rate of about 0.15 mils/side/minute or higher.
Claim 21
Dependent Claim
17 words
The solution of claim 12 which produces a post-milling hydrogen content of about 150 ppm or less.
Claim 22
Dependent Claim
71 words
A nitrate-free solution suitable for milling a titanium product at one or more temperatures in the range of about 16°-71° C. (60°-160° F.), said solution consisting essentially of: about 20-100 g/l of hydrofluoric acid; a hydrogen inhibitor selected from the group consisting of: about 55-650 g/l of sodium chlorate, about 180-650 g/l of ammonium peroxysulfate and at least about 10 g/l of hydrogen peroxide; and a balance of water and impurities.
Claim 23
Dependent Claim
71 words
A nitrate-free solution suitable for milling a titanium product at one or more temperatures in the range of about 16°-71° C. (60°-160° F.), said solution consisting essentially of: about 20-100 g/l of hydrofluoric acid; a hydrogen inhibitor selected from the group consisting of: about 55-650 g/l of sodium chlorate, about 180-650 g/l of ammonium peroxysulfate and at least about 10 g/l of hydrogen peroxide; and a balance of water and impurities.
Claim 24
Dependent Claim
14 words
The solution of claim 19 wherein milling occurs at about 21°-57° C. (70°-135° F.).
Claim 25
Dependent Claim
27 words
The solution of claim 19 wherein the titanium product is made from an alloy selected from the group consisting of: Ti-6Al-4V, Ti-6Al-6V-2Sn, Ti-10V-2Fe-3Al and commercially pure titanium.
Claim 26
Dependent Claim
13 words
The solution of claim 19 wherein the titanium product is a Ti-6Al-4V forging.
Claim 27
Dependent Claim
17 words
The solution of claim 19 which produces a post-milling hydrogen content of about 150 ppm or less.
Claim 28
Independent Claim
94 words
A method for chemically milling a metal workpiece comprising: (a) providing a substantially nitrate-free aqueous solution consisting essentially of about 20-100 g/l of hydrofluoric acid and at least one hydrogen inhibitor selected from the group consisting of: about 55-650 g/l of sodium chlorate, about 180-650 g/l of ammonium peroxysulfate, and at least about 10 g/l of hydrogen peroxide; (b) maintaining the solution at one or more temperatures in the range of about 16°-71° C. (60°-160° F.); and (c) immersing the workpiece in the solution to mill the workpiece surfaces in contact with the solution.
Claim 29
Independent Claim
94 words
A method for chemically milling a metal workpiece comprising: (a) providing a substantially nitrate-free aqueous solution consisting essentially of about 20-100 g/l of hydrofluoric acid and at least one hydrogen inhibitor selected from the group consisting of: about 55-650 g/l of sodium chlorate, about 180-650 g/l of ammonium peroxysulfate, and at least about 10 g/l of hydrogen peroxide; (b) maintaining the solution at one or more temperatures in the range of about 16°-71° C. (60°-160° F.); and (c) immersing the workpiece in the solution to mill the workpiece surfaces in contact with the solution.
Claim 30
Dependent Claim
15 words
The method of claim 24 wherein the solution contains about 20-150 g/l of hydrogen peroxide.
Claim 31
Dependent Claim
30 words
The method of claim 24 which further comprises one or more of the following steps before immersing step (c): (i) cleaning the workpiece; and (ii) masking areas of the workpiece.
Claim 32
Dependent Claim
42 words
The method of claim 24 which further comprises one or more of the following steps after workpiece immersion: (i) stirring or agitating the solution while the workpiece remains immersed therein; and (ii) rinsing the workpiece after it is removed from the solution.
Claim 33
Dependent Claim
14 words
The method of claim 24 wherein the workpiece is made from a titanium alloy.
Claim 34
Dependent Claim
29 words
The method of claim 28 wherein the workpiece is a forging made from a titanium alloy selected from the group consisting of: Ti-6Al-4V, Ti-6Al-6V-2Sn, Ti-10V-2Fe-3Al and commercially pure titanium.
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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) | 1996-09-27 | 1997-03-29 | 1997-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-27 | 2001-03-29 | 2001-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-27 | 2005-03-29 | 2005-09-28 | $7700.00 | Window Closed / Lapsed |