US4430170A
Expired / Lapsed
US
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Electrodeposition of refractory metal carbides
Assignee: United States Department of the Navy
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Filing: 1983-01-17
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Granted: 1984-02-07
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Expires: 2003-01-17
Abstract
Abstract A refractory metal carbide coating is electrodeposited onto an object, us a bath containing an alkali fluoride melt, an alkali carbonate dissolved in the melt, a refractory metal-containing compound also dissolved in the melt, and an anode composed of that refractory metal. The object to be coated is immersed into the bath as the anode, and a voltage is applied until the coating obtains the desired thickness. By this process, coatings such as tungsten carbide and tantalum carbide having a desired stoichiometric composition may be deposited on the surface of an object.
Inventors
- 👤 Kurt H. Stern
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:57
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/66
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
127 words
A process for the electrodeposition of a refractory metal carbide upon the surface of an object, the steps of which comprise: preparing an essentially pure alkali fluoride melt in an inert container; adding carbonate ions to said melt in the form of alkali carbonate: adding the refractory metal, the carbide of which is desired to be coated upon said object, to said alkali fluoride melt in the form of a soluble, metal-containing compound; immersing the elemental form of the refractory metal in said melt as an anode electrode; immersing the object desired to be coated into said melt as a cathode electrode; applying a voltage across said electrodes until said cathode has the desired thickness of coating of said carbide of said refractory metal upon its surface.
Claim 2
Dependent Claim
127 words
A process for the electrodeposition of a refractory metal carbide upon the surface of an object, the steps of which comprise: preparing an essentially pure alkali fluoride melt in an inert container; adding carbonate ions to said melt in the form of alkali carbonate: adding the refractory metal, the carbide of which is desired to be coated upon said object, to said alkali fluoride melt in the form of a soluble, metal-containing compound; immersing the elemental form of the refractory metal in said melt as an anode electrode; immersing the object desired to be coated into said melt as a cathode electrode; applying a voltage across said electrodes until said cathode has the desired thickness of coating of said carbide of said refractory metal upon its surface.
Claim 3
Dependent Claim
29 words
The process of claim 1 wherein said alkali fluoride melt consists essentially of a eutectic mixture of alkali fluorides chosen from the group consisting of LiF:KF, NaF:KF, and LiF:NaF:KF.
Claim 4
Dependent Claim
27 words
The process of claim 2 wherein the weight percent of carbonate ions added to said melt is about 0.6-6 percent, based on the weight of said melt.
Claim 5
Dependent Claim
15 words
The process of claim 3 wherein said alkali fluoride melt is the eutectic mixture, LiF:NaF:KF.
Claim 6
Dependent Claim
26 words
The process of claim 4 wherein said alkali carbonate is selected from the group consisting of Na 2 CO 3 and K 2 CO 3 .
Claim 7
Dependent Claim
15 words
The process of claim 5 wherein said alkali carbonate in K 2 CO 3 .
Claim 8
Dependent Claim
16 words
The process of claim 6 wherein the voltage applied across said electrodes is about 0.1-2.0 V.
Claim 9
Dependent Claim
24 words
The process of claim 7 wherein said refractory metal is selected from the group consisting of tantalum, molybdenum, titanium, hafnium, chromium, niobium and tungsten.
Claim 10
Dependent Claim
18 words
The process of claim 8 wherein said metal is selected from the group consisting of tantalum and tungsten.
Claim 11
Dependent Claim
21 words
The process of claim 9 wherein said metal is tantalum and said metal containing compound is Na 2 TaF 7 .
Claim 12
Dependent Claim
17 words
The process of claim 9 wherein said metal is tungsten and said metal-containing compound is sodium tungstate.
Claim 13
Dependent Claim
11 words
The process of claim 8 wherein said refractory metal is chromium.
Claim 14
Dependent Claim
11 words
The process of claim 8 wherein said refractory metal is molybdenum.
Claim 15
Dependent Claim
11 words
The process of claim 8 wherein said refractory metal is titanium.
Claim 16
Dependent Claim
15 words
The process of claim 14 wherein said metal-containing compound is K 2 TiF 6 .
Claim 17
Dependent Claim
11 words
The process of claim 8 wherein said refractory metal is zirconium.
Claim 18
Dependent Claim
11 words
The process of claim 8 wherein said refractory metal is niobium.
Claim 19
Dependent Claim
11 words
The process of claim 8 wherein said refractory metal is hafnium.
Claim 20
Dependent Claim
120 words
A process for the electrodeposition of tantalum carbide upon the surface of an object, the steps of which comprise: preparing an essentially pure melt of the eutectic mixture, LiF:NaF:KF, at about 750°-850° C.; adding 0.6 to 6 weight percent carbonate ions to said melt, based upon the weight of said melt, in the form of K 2 CO 3 ; adding tantalum to said melt in the form of Na 2 TaF 7 ; immersing elemental tantalum into said melt as an anode; immersing the object desired to be coated into said melt as a cathode; and applying about 0.1-2.0 V across said electrodes until said cathode has the desired thickness of coating of tantalum carbide metal upon its surface.
Claim 21
Dependent Claim
120 words
A process for the electrodeposition of tantalum carbide upon the surface of an object, the steps of which comprise: preparing an essentially pure melt of the eutectic mixture, LiF:NaF:KF, at about 750°-850° C.; adding 0.6 to 6 weight percent carbonate ions to said melt, based upon the weight of said melt, in the form of K 2 CO 3 ; adding tantalum to said melt in the form of Na 2 TaF 7 ; immersing elemental tantalum into said melt as an anode; immersing the object desired to be coated into said melt as a cathode; and applying about 0.1-2.0 V across said electrodes until said cathode has the desired thickness of coating of tantalum carbide metal upon its surface.
Claim 22
Dependent Claim
117 words
A process for the electrodeposition of a tungsten carbide upon the surface of an object, the steps of which comprise: preparing an essentially pure melt of the eutectic mixture, LiF:NaF:KF, at about 750°-850° C.; adding 0.6 to 6 weight percent carbonate ions to said melt, based upon the weight of said melt in the form of K 2 CO 3 ; adding tungsten to said melt in the form of sodium tungstate; immersing elemental tungsten in said melt as an anode; immersing the object desired to be coated into said melt as a cathode; and applying about 0.1-1.5 V across said electrodes until said cathode has the desired thickness of coating of tungsten carbide upon its surface.
Claim 23
Dependent Claim
117 words
A process for the electrodeposition of a tungsten carbide upon the surface of an object, the steps of which comprise: preparing an essentially pure melt of the eutectic mixture, LiF:NaF:KF, at about 750°-850° C.; adding 0.6 to 6 weight percent carbonate ions to said melt, based upon the weight of said melt in the form of K 2 CO 3 ; adding tungsten to said melt in the form of sodium tungstate; immersing elemental tungsten in said melt as an anode; immersing the object desired to be coated into said melt as a cathode; and applying about 0.1-1.5 V across said electrodes until said cathode has the desired thickness of coating of tungsten carbide upon its surface.
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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) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |