US3844859A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Titanium chemical milling etchant
Assignee: Boeing Co
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Filing: 1972-06-20
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Granted: 1974-10-29
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Expires: 1992-06-20
Abstract
Abstract A composition and a process for chemical milling titanium utilizing an aqueous nitric-hydrofluoric acid base etchant having a nitric acid content ranging from about 0.2 - 1.2 weight percent.
Inventors
- 👤 J Roni
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:52
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C23F1/26
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
109 words
A METHOD OF CHEMICAL MILLING TITANIUM TO REMOVE METAL FROM THE HORIZONTAL AND VERTICAL SURFACES OF THE TITANIUM AT ESSENTIALLY THE SAME UNIFORM RATE, THE STEPS COMPRISING: A. IMMERSING THE TITANIUM IN AN AQUEOUS ETCHING FLUID CONTAINING A CONCENTRATION OF HYDROFLUORIC ACID SUFFICIENT TO EFFECT AN ETCH RATE ON TITANIUM OF FROM ABOUT 0.0004 TO 0.0015 INCHES PER SIDE PER MINUTES, A SURFACE ACTIVE AGENT SELECTED OF MATERIALS CONSISTING ESSENTIALLY OF DODECYLBENZENE SULFONIC ACID AND LINEAR ALKYL SULFONIC ACID IN AMOUNTS SUFFICIENT TO CONTROL SURFACE TENSION OF THE ETCHING SOLUTION AT FROM ABOUT 28 TO 60 DYNES PER CM., AND ABOUT 0.2 WEIGHT PERCENT OF NITRIC ACID, SAID AQUEOUS
Claim 2
Independent Claim
109 words
A METHOD OF CHEMICAL MILLING TITANIUM TO REMOVE METAL FROM THE HORIZONTAL AND VERTICAL SURFACES OF THE TITANIUM AT ESSENTIALLY THE SAME UNIFORM RATE, THE STEPS COMPRISING: A. IMMERSING THE TITANIUM IN AN AQUEOUS ETCHING FLUID CONTAINING A CONCENTRATION OF HYDROFLUORIC ACID SUFFICIENT TO EFFECT AN ETCH RATE ON TITANIUM OF FROM ABOUT 0.0004 TO 0.0015 INCHES PER SIDE PER MINUTES, A SURFACE ACTIVE AGENT SELECTED OF MATERIALS CONSISTING ESSENTIALLY OF DODECYLBENZENE SULFONIC ACID AND LINEAR ALKYL SULFONIC ACID IN AMOUNTS SUFFICIENT TO CONTROL SURFACE TENSION OF THE ETCHING SOLUTION AT FROM ABOUT 28 TO 60 DYNES PER CM., AND ABOUT 0.2 WEIGHT PERCENT OF NITRIC ACID, SAID AQUEOUS
Claim 3
Dependent Claim
27 words
A method of chemical milling titanium as recited in claim 1, further comprising: adding from about 0.07 to 2.9 weight percent of ammonium bifluoride to the etchant.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |