Patent US3753815A successfully refreshed from Google Patents.
US3753815A
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US
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Method and bath for treating titanium
Assignee: Armco Inc
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Filing: 1971-09-22
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Granted: 1973-08-21
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Expires: 1991-09-22
Abstract
Abstract Method of treating titanium and titanium alloys, especially hotworked products such as bar, rod, wire and various flat-rolled forms so as to remove seams, fissures and the like, as well as a desired amount of surface metal. The products are immersed in a bath comprising some 5 percent to 15 percent by volume hydrofluoric acid, with remainder phosphoric acid and water, maintained at such temperature and for such time as to remove a desired quantity of metal and yield a dull, satin-like finish free of pitting and ready for further processing. Where desired, the products may be subjected to a preliminary treatment in a molten salt bath, such as sodium hydroxide, and washed in water, this to best condition the products for metal removal.
Inventors
- 👤 A Burton
- 👤 G Pierpont
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:38
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C23F1/26; C23F3/00; C23F3/04; C23F3/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
67 words
Method of chemically removing metal from hot-worked titanium products such as bar, rod, wire which comprises subjecting the same to molten sodium hydRoxide; washing in water; and then subjecting to a solution essentially consisting of about 5 percent to 15 percent by volume of hydrofluoric acid, about 5 percent to about 25 percent by volume of phosphoric acid, and water at least about 60 percent by volume.
Claim 2
Independent Claim
73 words
The method of chemically removing metal from the surface of titanium products which comprises treating the products in a bath essentially consisting of about 5 percent to about 15 percent by volume hydrofluoric acid, about 5 percent to about 25 percent by volume phosphoric acid, and water at least about 60 percent by volume while maintaining the bath at a temperature of at least about 115* F. but not exceeding about 145* F.
Claim 3
Independent Claim
98 words
The method of chemically removing hairlines, surface cracks, fissures and surface metal generally from titanium products which comprises treating the products in an aqueous bath essentially consisting of about 10 percent to about 15 percent by volume hydrofluoric acid, about 5 percent to about 15 percent by volume phosphoric acid, and water at least about 60 percent by volume while maintaining the bath at a temperature of about 120* F. to about 140* F. for such time as to remove a desired quantity of metal and give a surface of dull satin finish without either pitting or polish.
Claim 4
Independent Claim
90 words
The method of chemically removing hairlines, surface cracks, fissures and surface metal generally from titanium products which comprises treating the products in an aqueous bath essentially consisting of about 7 percent to about 10 percent by volume hydrofluoric acid, about 5 percent to about 15 percent by volume phosphoric acid, and water at least about 60 percent by volume while the bath is maintained at a temperature of about 120* to 140* F. and for such time as to give a surface of dull satin finish without pitting or polish.
Claim 5
Independent Claim
74 words
The method of chemically removing metal from the surface of titanium products with maximum rate of metal removal consistent with minimum hydrogen absorption which comprises treating the products in an aqueous bath essentially consisting of about 10 percent by volume hydrofluoric acid and about 10 percent by volume phosphoric acid, and water at least about 60 percent by volume while maintaining the bath at a temperature of about 120* F. to about 140* F.
Claim 6
Independent Claim
93 words
The method of chemically removing metal from the surface of titanium products which comprises treating the products in an aqueous bath essentially consisting of about 5 percent to about 15 percent by volume hydrofluoric acid, about 5 percent to about 25 percent by volume phosphoric acid, and water at least about 60 percent by volume; maintaining the bath at a temperature of about 120* to about 140* F.; and when the rate of metal removal has slowed to a value less than about 0.5 mils per minute spiking the bath with hydrofluoric acid.
Claim 7
Independent Claim
125 words
The method of chemically removing metal from the surface of titanium products which comprises treating the products in an aqueous bath essentially consisting of about 5 percent to about 15 percent by volume hydrofluoric acid, about 5 percent to about 25 percent by volume phosphoric acid, and water at least about 60 percent by volume while the bath is maintained at a temperature of about 120* F. to about 140* F. to achieve a surface of dull satin finish without pit or polish; and when the rate of metal removal falls below about 0.5 mils per minute, removing sludge from the bottom of the bath and spiking the same with hydrofluoric acid in the amount of about 2 percent to about 15 percent by volume.
Claim 8
Dependent Claim
46 words
A bath for chemically removing metal from titanium products essentially consisting of about 5 percent to about 15 percEnt by volume hydrofluoric acid, about 5 percent to about 25 percent by volume phosphoric acid, and water in the amount of at least 60 percent by volume.
References Cited (Backward Citations)
US3383255A
Cited
US3562013A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |