US1933319A - Electroplating tantalum - Google Patents
Electroplating tantalum Download PDFInfo
- Publication number
- US1933319A US1933319A US471081A US47108130A US1933319A US 1933319 A US1933319 A US 1933319A US 471081 A US471081 A US 471081A US 47108130 A US47108130 A US 47108130A US 1933319 A US1933319 A US 1933319A
- Authority
- US
- United States
- Prior art keywords
- tantalum
- metal
- bath
- electroplating
- current densities
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 title description 31
- 229910052715 tantalum Inorganic materials 0.000 title description 28
- 238000009713 electroplating Methods 0.000 title description 6
- 238000000034 method Methods 0.000 description 13
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 8
- 239000002184 metal Substances 0.000 description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 6
- 238000000151 deposition Methods 0.000 description 6
- 230000001464 adherent effect Effects 0.000 description 5
- 239000003513 alkali Substances 0.000 description 5
- 239000010953 base metal Substances 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 230000004927 fusion Effects 0.000 description 5
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 4
- 239000002253 acid Substances 0.000 description 4
- -1 alkali metal tantalum halide compound Chemical class 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 229910052750 molybdenum Inorganic materials 0.000 description 4
- 239000011733 molybdenum Substances 0.000 description 4
- 229910052759 nickel Inorganic materials 0.000 description 4
- 239000003870 refractory metal Substances 0.000 description 4
- 239000002585 base Substances 0.000 description 3
- 230000001427 coherent effect Effects 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 235000011164 potassium chloride Nutrition 0.000 description 3
- 239000001103 potassium chloride Substances 0.000 description 3
- NROKBHXJSPEDAR-UHFFFAOYSA-M potassium fluoride Chemical compound [F-].[K+] NROKBHXJSPEDAR-UHFFFAOYSA-M 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005868 electrolysis reaction Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- BPUBBGLMJRNUCC-UHFFFAOYSA-N oxygen(2-);tantalum(5+) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ta+5].[Ta+5] BPUBBGLMJRNUCC-UHFFFAOYSA-N 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 239000011698 potassium fluoride Substances 0.000 description 2
- APLLYCDGAWQGRK-UHFFFAOYSA-H potassium;hexafluorotantalum(1-) Chemical compound [F-].[F-].[F-].[F-].[F-].[F-].[K+].[Ta+5] APLLYCDGAWQGRK-UHFFFAOYSA-H 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 150000003482 tantalum compounds Chemical class 0.000 description 2
- 229910001936 tantalum oxide Inorganic materials 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 239000010937 tungsten Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 229910001508 alkali metal halide Inorganic materials 0.000 description 1
- 150000008045 alkali metal halides Chemical class 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 235000003270 potassium fluoride Nutrition 0.000 description 1
- 238000005488 sandblasting Methods 0.000 description 1
- 238000007790 scraping Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/66—Electroplating: Baths therefor from melts
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/922—Static electricity metal bleed-off metallic stock
- Y10S428/9265—Special properties
- Y10S428/929—Electrical contact feature
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/922—Static electricity metal bleed-off metallic stock
- Y10S428/9335—Product by special process
- Y10S428/934—Electrical process
- Y10S428/935—Electroplating
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12771—Transition metal-base component
- Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
- Y10T428/12819—Group VB metal-base component
Definitions
- This invention relates to the preparation of -metals and more particularly to the preparation of rare refractory metals by the electrolytic decomposition of rare refractory metal compounds 5 in fused baths.
- tantalum has been applied to many uses. Because of its chemical inertness and high melting point it has been proposed as a substitute for platinum in crucibles and similar chemical ware.
- tantalum as an electrode or as a gas clean up agent and filament is restricted, however, by reason of the fact that the tantalum lacks the rigidity which is characteristic of the refractory metals, tungsten and molybdenum, for example.
- the physical characteristics of tantalum which permit its ready mechanical deformation to desired shapes and sizes limit the application of the same in the arts.
- a process for (Cl. cor-19)" depositing tantalum metal powder upon a cathode In the practice of the invention set forth in this copending application it was one of the objects to prepare the tantalum in a reasonably coarse state, loosely adherent to the co cathode so that the same may be subsequently removed therefrom by mechanical means, such as scraping. In orderto obtain this type of deposit upon the cathode current densities ranging from 0.5 to 1.0 amperes per cm (50-100 amperes per decimeter were employed.
- a fusion mixture comprising potassium chloride, potassium fluoride, potassium tantalum fluoride and tantalum oxide in the following relative proportion is employed: so)
- the metal base thus prepared and immersed in the bath is given a final cleansing by making the same temporarily the anode in the bath so as to subject the same to anodic solution effects and desced to relatively high temperatures in the then is made the cathode.
- a current density of approximately .01 to 0.1 amperes per cm (1 to 10 amperes per decimeter is employed in effecting electro-plating of tantalum to the base metal.
- the specific current density employed will vary materially with the different base metals bein plated as will also the time interval necessary to effect a reasonably good deposit.
- the anode electrode In the surfacing of a crucible, for example, the anode electrode must be shaped in the approximate convolution of the crucible. In the surfacing of a radio tube plate electrode it is preferable to electroplate the surface of a sheet of the base metal, such as nickel or molybdenum and thereafter shape the electrode therefrom. In the surfacing of wire, filament and the like it is preferable to do the same in a continuous manner providing means exterior to the bath for cleansin the filament prior to entering the bath, said means depending primarily upon the nature of the base filament employed.
- the type of coating obtained by the practice of the above identified process can best be ascertained by immersing the coated metal in hot dilute nitric acid for an interval of time sufiicient to indicate whether the base element is being attacked by the acid.
- the tantalum is not touched by this acid.
- the articles also may be subjected to measw 1.
- the method of forming a continuous adhervent electro-plated tantalum surface upon an electrically conductive body comprising immersing said body in a fused bath comprised of alkali halide compounds containing a proportion of an ionized tantalum compound and electrolytically depositing the tantalum thereon at relatively low current densities ranging from 1 to 10 amperes per square decimeter.
- the method of electrolytically depositing an adherent coating of tantalum upon an 'elctrically conductive body comprising immersing said body in a fused bath comprised of alkali halide compounds containing a proportion of an ionized tantalum compound and electrolytically depositing the tantalum thereon at relatively low current densities ranging from 1 to 10 amperes per square decimeter.
- the method of electroplating an adherent continuous tantalum film comprising immersing an electrically conducting body in a fused bath comprised of alkali halide compounds, a proportion of a double alkali metal-tantalum fluoride compound, and electrolytically depositing the tantalum on said body at relatively low current densities ranging from 1 to 10 amperes per square decimeter.
- the method of electroplating an adherent continuous tantalum film comprising immersing an electrically conducting body in a fused bath comprised of potassium chloride and potassium fluoride compounds, a proportion of potassium tantalum fluoride and a proportion of tantalum oxide,'and electrolytically depositing the tantalum on said body at cathode current densities ranging from 1.0 to 10.0 amperes per square decimeter. 5
- an electri cally conductive body surfaced at least in part with a relatively smooth, continuous film of electrolytically. deposited tantalum, said film being in the form of an even coherent layer which is firmly adherent to the conductive body.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electroplating And Plating Baths Therefor (AREA)
Description
Patented Oct. 31, 1933 UNITED- STATES PATENT OFFICE ELECTROPLATING TAN'IALUM Pennsylvania No Drawing. Application July 26, 1930 Serial No. 471,081
Claims.
This invention relates to the preparation of -metals and more particularly to the preparation of rare refractory metals by the electrolytic decomposition of rare refractory metal compounds 5 in fused baths.
In compending application Serial No. 275,264 filed May 4, 1928 and entitled Method of producing tantalum and other rare refractory metals by electrolysis of fused compounds, there is disclosed a method of producing tantalum metal powder by the electrolytic decomposition of a fused bath comprised of alkali metal halides containing a proportion of a double alkali metal tantalum halide compound. The tantalum metal powder thus prepared is recovered from the fusion mixture by lixiviation methods and subjected to a vacuum sintering process to render the same coherent. The coherent tantalum metal thus obtained is substantially pure and may be readily 2o worked down into articles such as wire, rod, sheet,
filament and the like.
Heretofore in the arts tantalum has been applied to many uses. Because of its chemical inertness and high melting point it has been proposed as a substitute for platinum in crucibles and similar chemical ware.
In electric discharge devices, such as electron discharge devices of the evacuated type, gaseous conduction devices, radio tubes, X-ray tubes, in-
candescent lamps and the like it has been proposed to employ tantalum as electrode material,
gas clean up agent, filament and the like. The successful application of tantalum as an electrode or as a gas clean up agent and filament is restricted, however, by reason of the fact that the tantalum lacks the rigidity which is characteristic of the refractory metals, tungsten and molybdenum, for example. The physical characteristics of tantalum which permit its ready mechanical deformation to desired shapes and sizes limit the application of the same in the arts.
It is one of the objects of the present invention to facilitate the use andapplication of tantalum in'the arts. It is another object of this invention to provide tantalum surfaced materials which are useful in the arts.
It is another object of this invention to provide a process for electroplating tantalum upon metal surfaces. I Other objects and advantages will become apparent as the invention is more fully disclosed. In copending application Serial No. 275,264 above identified there is disclosed a process for (Cl. cor-19)" depositing tantalum metal powder upon a cathode. In the practice of the invention set forth in this copending application it was one of the objects to prepare the tantalum in a reasonably coarse state, loosely adherent to the co cathode so that the same may be subsequently removed therefrom by mechanical means, such as scraping. In orderto obtain this type of deposit upon the cathode current densities ranging from 0.5 to 1.0 amperes per cm (50-100 amperes per decimeter were employed.
We have found that when current densities of a much lower order are employed that the tanta-= lum thus deposited may be made to adhere to the cathode surface to form a smooth continuous film thereon which is substantially impervious to acids and to gases.
As a specific example of the present invention we form an electroplated tantalum coating upon iron, nickel, molybdenum, tungsten and the like is surfaces in the following manner:
A fusion mixture comprising potassium chloride, potassium fluoride, potassium tantalum fluoride and tantalum oxide in the following relative proportion is employed: so)
300 grams -l KCl 120 grams KF 100 grams KaTaF'z 25 grams TazOa This fusion mixture is placed in a graphite crucible and brought to fusion by any convenient means. The approximate melting point of this bath is 700 to 750 C. The bath is maintained during electrolysis at a temperature approximat- 9o ing 750 C. The base metal to be surfaced with the tantalum is immersed in the fused bath and allowed to remain therein until it has attained approximately the same temperature as the bath. Due to the corrosive action of the fusion mixture the surface of the immersed metal will be substantially cleansed of all deleterious oxides. It is better, however, to subject the metal prior to immersion to the usual surface cleansing processes, such as subjecting the metal body to the action of a reducing gas'such as hydrogen, etching the surface with acid or alkali solutions or sand blasting. The latter method is to be preferred as the roughened surface materially facilitates the retention of the deposited tantalum thereon.
The metal base thus prepared and immersed in the bath is given a final cleansing by making the same temporarily the anode in the bath so as to subject the same to anodic solution effects and desced to relatively high temperatures in the then is made the cathode. A current density of approximately .01 to 0.1 amperes per cm (1 to 10 amperes per decimeter is employed in effecting electro-plating of tantalum to the base metal.
The specific current density employed will vary materially with the different base metals bein plated as will also the time interval necessary to effect a reasonably good deposit.
As an illustration reference should be made to the following table wherein is given some representative current densities employed in the surfacing of nickel, iron and molybdenum articles with tantalum.
Ampere Base metal cm, in per Time minutes Typg of bath cm per coating 14 217 15 3. 0 Too coarse 10 .05 10 5 Good 12 041 15 62 Best 8 062 30 1. 8 Good 18 028 l. 5 Good The above table illustrates the type of coating obtained in the plating of strips of sheet metal with different current densities. In the plating of shaped articles, such as crucibles, radio tube plate (or anode electrodes) or the surfacing of lengths of wire, filament and the like, variations in the current densities that may be employed and in the arrangement of elements within the bath must be made.
In the surfacing of a crucible, for example, the anode electrode must be shaped in the approximate convolution of the crucible. In the surfacing of a radio tube plate electrode it is preferable to electroplate the surface of a sheet of the base metal, such as nickel or molybdenum and thereafter shape the electrode therefrom. In the surfacing of wire, filament and the like it is preferable to do the same in a continuous manner providing means exterior to the bath for cleansin the filament prior to entering the bath, said means depending primarily upon the nature of the base filament employed.
The type of coating obtained by the practice of the above identified process can best be ascertained by immersing the coated metal in hot dilute nitric acid for an interval of time sufiicient to indicate whether the base element is being attacked by the acid. The tantalum is not touched by this acid.
We have found that when a nickel or iron sheet or crucible shaped article has been so surfaced with tantalum that the article maybe incanopen air without substantial oxidation or deterioration. The articles also may be subjected to measw 1. The method of forming a continuous adhervent electro-plated tantalum surface upon an electrically conductive body comprising immersing said body in a fused bath comprised of alkali halide compounds containing a proportion of an ionized tantalum compound and electrolytically depositing the tantalum thereon at relatively low current densities ranging from 1 to 10 amperes per square decimeter.
2. The method of electrolytically depositing an adherent coating of tantalum upon an 'elctrically conductive body comprising immersing said body in a fused bath comprised of alkali halide compounds containing a proportion of an ionized tantalum compound and electrolytically depositing the tantalum thereon at relatively low current densities ranging from 1 to 10 amperes per square decimeter.
3. The method of electroplating an adherent continuous tantalum film comprising immersing an electrically conducting body in a fused bath comprised of alkali halide compounds, a proportion of a double alkali metal-tantalum fluoride compound, and electrolytically depositing the tantalum on said body at relatively low current densities ranging from 1 to 10 amperes per square decimeter.
4. The method of electroplating an adherent continuous tantalum film comprising immersing an electrically conducting body in a fused bath comprised of potassium chloride and potassium fluoride compounds, a proportion of potassium tantalum fluoride and a proportion of tantalum oxide,'and electrolytically depositing the tantalum on said body at cathode current densities ranging from 1.0 to 10.0 amperes per square decimeter. 5
5. As an article of manufacture, an electri= cally conductive body surfaced at least in part with a relatively smooth, continuous film of electrolytically. deposited tantalum, said film being in the form of an even coherent layer which is firmly adherent to the conductive body.
Mil
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US471081A US1933319A (en) | 1930-07-26 | 1930-07-26 | Electroplating tantalum |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US471081A US1933319A (en) | 1930-07-26 | 1930-07-26 | Electroplating tantalum |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US1933319A true US1933319A (en) | 1933-10-31 |
Family
ID=23870170
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US471081A Expired - Lifetime US1933319A (en) | 1930-07-26 | 1930-07-26 | Electroplating tantalum |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US1933319A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2709154A (en) * | 1948-04-05 | 1955-05-24 | Josephine Maria Hansgirg | Corrosion resisting coatings |
| US2773023A (en) * | 1954-04-26 | 1956-12-04 | Horizons Titanium Corp | Removal of oxygen from metals |
| US2786809A (en) * | 1953-09-30 | 1957-03-26 | Horizons Titanium Corp | Electrolytic cladding |
| US2798988A (en) * | 1954-01-28 | 1957-07-09 | Mallory & Co Inc P R | Electrolytic capacitor |
| US2828251A (en) * | 1953-09-30 | 1958-03-25 | Horizons Titanium Corp | Electrolytic cladding process |
| US2872389A (en) * | 1946-12-26 | 1959-02-03 | Charles J Slunder | Treatment of uranium surfaces |
| US4488941A (en) * | 1982-09-27 | 1984-12-18 | Sprague Electric Company | Electroplating method for producing porous tantalum capacitor electrode |
-
1930
- 1930-07-26 US US471081A patent/US1933319A/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2872389A (en) * | 1946-12-26 | 1959-02-03 | Charles J Slunder | Treatment of uranium surfaces |
| US2709154A (en) * | 1948-04-05 | 1955-05-24 | Josephine Maria Hansgirg | Corrosion resisting coatings |
| US2786809A (en) * | 1953-09-30 | 1957-03-26 | Horizons Titanium Corp | Electrolytic cladding |
| US2828251A (en) * | 1953-09-30 | 1958-03-25 | Horizons Titanium Corp | Electrolytic cladding process |
| US2798988A (en) * | 1954-01-28 | 1957-07-09 | Mallory & Co Inc P R | Electrolytic capacitor |
| US2773023A (en) * | 1954-04-26 | 1956-12-04 | Horizons Titanium Corp | Removal of oxygen from metals |
| US4488941A (en) * | 1982-09-27 | 1984-12-18 | Sprague Electric Company | Electroplating method for producing porous tantalum capacitor electrode |
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