US2872389A - Treatment of uranium surfaces - Google Patents
Treatment of uranium surfaces Download PDFInfo
- Publication number
- US2872389A US2872389A US718623A US71862346A US2872389A US 2872389 A US2872389 A US 2872389A US 718623 A US718623 A US 718623A US 71862346 A US71862346 A US 71862346A US 2872389 A US2872389 A US 2872389A
- Authority
- US
- United States
- Prior art keywords
- uranium
- anodizing
- approximately
- percent
- phosphoric acid
- 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
Links
- 229910052770 Uranium Inorganic materials 0.000 title claims description 41
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 title claims description 41
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 34
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 32
- 238000007743 anodising Methods 0.000 claims description 25
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 16
- 238000009713 electroplating Methods 0.000 claims description 10
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 12
- 239000010953 base metal Substances 0.000 description 10
- 239000002184 metal Substances 0.000 description 9
- 229910052751 metal Inorganic materials 0.000 description 9
- 238000000576 coating method Methods 0.000 description 7
- 239000013078 crystal Substances 0.000 description 7
- 238000007747 plating Methods 0.000 description 7
- 230000001464 adherent effect Effects 0.000 description 6
- 229910052759 nickel Inorganic materials 0.000 description 6
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 239000004519 grease Substances 0.000 description 4
- 150000002739 metals Chemical class 0.000 description 4
- 229910017604 nitric acid Inorganic materials 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 238000007598 dipping method Methods 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000008399 tap water Substances 0.000 description 2
- 235000020679 tap water Nutrition 0.000 description 2
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004070 electrodeposition Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 238000005488 sandblasting Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000002904 solvent Substances 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
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/34—Pretreatment of metallic surfaces to be electroplated
- C25D5/46—Pretreatment of metallic surfaces to be electroplated of actinides
Definitions
- each layer of atoms must be influenced by the orientation of the atoms of the preceding layer. Obviously for the growth of an adhered deposit it is necessary that the deposited metal be in intimate. atomic contact with the base metal crystalline structure. Under these conditions, the crystals of the deposited layer may be formed as a direct extension of the crystals in the base metal. Such a coating becomes an integral part of the article being plated.
- the adherenceof plating metals on uranium is thus dependent upon the intimate contact of crystals of the plated metal with the crystals of the base metal, uranitun.
- uranium in addition to the usual cleaning and pickling procedures to insure the removal of grease and heavy oxide films, uranium must be. given a special pretreatment in which the essential factor involved appears to be attacking of the base metal uniformly to remove crystals distorted by surface-working, so that the surface exposed for plating has the basic crystalline structure of the base metal. After such treatment, the electroplate takes on its adherence 2,872,38 Patented ch. 3, 1959 2 vide a process for treating uranium surfaces to render them suitable for the electroplating thereon of firmly bonded adherent coatings.
- the objects of this invention are accomplished by anodizing the uranium surface in a bath of a solu .tion of phosphoric acid containing hydrochloric acid.
- H PO Anodizing of uranium surfaces in phosphoric acid, H PO has been found to cause electropolishing of the uranium surfaces, and electroplates do not adhere well to uranium after such treatment.
- the anodizing is done with a solution of phosphoric acid into which hydrochloric acid has been introduced. This is found to produce a highly desirable result which is not obtainable from either of the above substances alone.
- a proper solution of the black deposit may be formed on the uranium.
- This black deposit or film may be removed by a short dip in nitric acid and the resulting surface has a smooth grey appearance of very fine texture which is found to be capable of being electroplated with such metals as nickel and copper with an excellent bonding of the deposited plate to the uranium base.
- Table I the results of a series of experiments designed to determine the optimum concentrations of phosphoric acid and hydrochloric acid.
- the standard for determining the optimum results was of necessity highly empirical.
- the test was performed by electroplating nickel on the surfaces anodized in the various baths shown in the table and thereafter filing an edge of the sample and examining the filings for separation of nickel. plate and base metal.
- the adhesion qualities of the platings obtained were rated on the basis of 10 for the best results obtained, decreasing numerals representing decreasing adherent qualities of the platings.
- the surface is first cleaned of grease in a solvent such as carbon tetrachloride by rinsing and wiping.
- the major portion of the oxide film is then removed by dipping in an acid such as 70 percent nitric acid for a time of the order of 1 /2 minutes.
- the uranium is then rinsed in tap water. It is then anodized in the bath consisting of a 50 percent solution of phosphoric acid containing cc. per liter of concentrated hydrochloric acid for ten minutes at a temperature of 40 C. with a current density of 0.5 ampere per square inch of surface.
- the uranium is then again rinsed in tap Water and the film formed in the anodizing is'then removed by dipping for a short time, of the order of 20 to 50 seconds, in 70 percent nitric acid. After a further rinse the surface is electroplated.
- the step of anodizing the surface of the uranium in a bath comprising a solution of approximately 50 percent by weight of phosphoric acid containing about 20 cc. per liter of concentrated hydrochloric acid at a temperature of about to C. for approximately 10 minutes, the anodizing current density being about 0.5 ampere per square inch of said surface.
- the step of anodizing the surface of the uranium in a bath comprising a solution of approximately 20 percent to 60 percent by weight of phosphoric acid containing about 20 cc. per liter of concentrated hydrochloric acid at a tem perature of about 35 to 45 C; for approximately 10 minutes, the anodizing current density beingabout 0.5 amperes per square inch of said surface.
- step of anodizing the surface of the uranium in a bath comprising a solution of approximately 20 percent to 60 percent by weight of phosphoric acid containing approximately 20 to cc. per liter of concentrated hydrochloric acid at a temperature of about 35 to 45 C.,. the anodizing current being in the range of 0.125 to 1.0 ampere per square inch of said surface. 4.
- the step of anodizing the surface of theuranium in a bath comprising a solution of approximately 20 percent to 60 percent by weight of phosphoric acid containing approximately 203 to 100 cc; per liter of concentrated hydrochloric acid.
- the step of anodizing the surface of the uranium in a bath comprising" a solution of from 20 to 60 percent by weight of phosphoric acid containing approximately 20 cc. per liter of concentrated hydrochloric acid.
- a process of treating uranium the step of anodizing the surface of the uranium in a bath comprising a solution of from 20 to 60 percent by weight of phosphoric acid containing approximately 20 to 100 cc. per liter of concentrated hydrochloric acid.
- a process of treating a uranium surface comprising the steps of removing grease, removing oxide film by an acid dip, anodizing in a bath'containing from 20 to 60 percent by weight of phosphoric acid and from 20 to 100 cc. per liter of concentratedhydrochloric acid, removing the film resulting from anodizing and thereafter electroplating upon said surface.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electroplating Methods And Accessories (AREA)
Description
2,872,389 TREATMENT GE URANIUM SURFACES SerialNo. 718,623 9'Claims. (Cl. 204-15 N D w n This. inventionrelatesto an improvement in methods forelectroplating metals upon uranium surfaces. More particularly the invention relates to an improved method of preparing uranium surfaces for electroplating.
The adhesion of electrodeposited coatings to a base metal depends to a greatextent on intimate contact of the coating and the base. metal. .In order for a crystalline deposit to be continuous, each layer of atoms must be influenced by the orientation of the atoms of the preceding layer. Obviously for the growth of an adhered deposit it is necessary that the deposited metal be in intimate. atomic contact with the base metal crystalline structure. Under these conditions, the crystals of the deposited layer may be formed as a direct extension of the crystals in the base metal. Such a coating becomes an integral part of the article being plated.
The above theory of electroplating has been found to be of fundamental importance in the plating of adherent coatings on uranium. Absolute cleanliness of the metal surface priorto plating can bedefined as that condition whichpermits the structure of the base metal to be continued by. electrodeposition. The presence of grease, oxides or other extraneous materials markedly reduces adhesion. In most platingwork, a roughened surface such as is produced by. sandblasting improves the bond between coating and base metal.
The adherenceof plating metals on uranium is thus dependent upon the intimate contact of crystals of the plated metal with the crystals of the base metal, uranitun.
When such intimate contact is achieved, it is believed thatv the initial crystals of the depositedlayer of, for example, r
nickel or copper, are-formed as direct extensionsof the crystals of uranium so that the plated coating becomes an integral part of the specimen being plated. Thus, in addition to the usual cleaning and pickling procedures to insure the removal of grease and heavy oxide films, uranium must be. given a special pretreatment in which the essential factor involved appears to be attacking of the base metal uniformly to remove crystals distorted by surface-working, so that the surface exposed for plating has the basic crystalline structure of the base metal. After such treatment, the electroplate takes on its adherence 2,872,38 Patented ch. 3, 1959 2 vide a process for treating uranium surfaces to render them suitable for the electroplating thereon of firmly bonded adherent coatings.
It is a more specific object of the invention .to provide an anodizing bathfor anodic treatment of uranium to produce such surfaces priorto electroplating.
Generally the objects of this invention are accomplished by anodizing the uranium surface in a bath of a solu .tion of phosphoric acid containing hydrochloric acid.
The methods that have proven successful for the deposition of adherent electroplates to uranium involve anodizing of the uranium in solutions containing chloride ions. Hydrochloric acid reacts very violently with uranium even by simple immersion at room temperature. However, uninhibited solutions of hydrochloric acid have not proven satisfactory for pretreating purposes for the .following reasons: (1) a very non-uniform surface is produced; (2) the reaction once started is diflicult. to control; and (3) adherent electroplates are not found to be obtained on surfaces thus prepared.
Anodizing of uranium surfaces in phosphoric acid, H PO has been found to cause electropolishing of the uranium surfaces, and electroplates do not adhere well to uranium after such treatment.
In the present invention the anodizing is done with a solution of phosphoric acid into which hydrochloric acid has been introduced. This is found to produce a highly desirable result which is not obtainable from either of the above substances alone. By anodizing the uranium in a proper solution of the black deposit may be formed on the uranium. This black deposit or film may be removed by a short dip in nitric acid and the resulting surface has a smooth grey appearance of very fine texture which is found to be capable of being electroplated with such metals as nickel and copper with an excellent bonding of the deposited plate to the uranium base.
The exact theory which accounts for this result is not known. The combination of the electropolishing effect of the phosphoric acid and the pitting action of the hydrochloric acid seems to result in a controlled attack on the surface of the metal which renders the electroplate firmly adherent.
In the following Table I are shown the results of a series of experiments designed to determine the optimum concentrations of phosphoric acid and hydrochloric acid. The standard for determining the optimum results was of necessity highly empirical. The test was performed by electroplating nickel on the surfaces anodized in the various baths shown in the table and thereafter filing an edge of the sample and examining the filings for separation of nickel. plate and base metal. The adhesion qualities of the platings obtained were rated on the basis of 10 for the best results obtained, decreasing numerals representing decreasing adherent qualities of the platings.
by virtue of following the fundamental crystalline contour of the base metal.
It is the principal object of the present invention to pro- It appears from the above table that optimum results. are obtained in cleaning the uranium surface preparatory to electroplating by using a solution of phosphoric acid.
above substances, a uniform temperature of the bath and of current density in the anodizing treatment. The results of these tests are shown in Table II which follows, the numerals indicating the quality of the bond achieved in plating nickel as in Table I.
Table 11 Current density, amperes per square inch Temperature Here again, although the ratings shown in the table do not allow exact determination of the optimum conditions, it has been found that a bath temperature of approximately 35 to 45 C. and an anodizing current density of approximately 0.5 ampere per square inch of surface represent optimum conditions. This determination was likewise made of the basis of sub-gradations which are not shown in the table. It has been found that the optimum time for the anodizing treatment is ten minutes.
A complete procedure which has been found to produce an excellent electroplating of such metals as nickel and copper on uranium surfaces is as follows:
The surface is first cleaned of grease in a solvent such as carbon tetrachloride by rinsing and wiping. The major portion of the oxide film is then removed by dipping in an acid such as 70 percent nitric acid for a time of the order of 1 /2 minutes. The uranium is then rinsed in tap water. It is then anodized in the bath consisting of a 50 percent solution of phosphoric acid containing cc. per liter of concentrated hydrochloric acid for ten minutes at a temperature of 40 C. with a current density of 0.5 ampere per square inch of surface.
The uranium is then again rinsed in tap Water and the film formed in the anodizing is'then removed by dipping for a short time, of the order of 20 to 50 seconds, in 70 percent nitric acid. After a further rinse the surface is electroplated.
What is claimed is:
1. In the process of electroplating uranium, the step of anodizing the surface of the uranium in a bath comprising a solution of approximately 50 percent by weight of phosphoric acid containing about 20 cc. per liter of concentrated hydrochloric acid at a temperature of about to C. for approximately 10 minutes, the anodizing current density being about 0.5 ampere per square inch of said surface.
2. In a process of cleaning a uraniumsurface, the step of anodizing the surface of the uranium in a bath comprising a solution of approximately 20 percent to 60 percent by weight of phosphoric acid containing about 20 cc. per liter of concentrated hydrochloric acid at a tem perature of about 35 to 45 C; for approximately 10 minutes, the anodizing current density beingabout 0.5 amperes per square inch of said surface.
3. In a process of cleaning a uranium surface,'the.
step of anodizing the surface of the uranium in a bath comprising a solution of approximately 20 percent to 60 percent by weight of phosphoric acid containing approximately 20 to cc. per liter of concentrated hydrochloric acid at a temperature of about 35 to 45 C.,. the anodizing current being in the range of 0.125 to 1.0 ampere per square inch of said surface. 4. In a process of treating uranium, the step of anodizing the surface of theuranium in a bath comprising a solution of approximately 20 percent to 60 percent by weight of phosphoric acid containing approximately 203 to 100 cc; per liter of concentrated hydrochloric acid.
5. In a process of treating uranium, the step of anodizing the surface of the uranium in a bath comprising" a solution of from 20 to 60 percent by weight of phosphoric acid containing approximately 20 cc. per liter of concentrated hydrochloric acid.
6. In a process of treating uranium, the step of anodizing the surface of the uranium in a bath comprising a solution of from 20 to 60 percent by weight of phosphoric acid containing approximately 20 to 100 cc. per liter of concentrated hydrochloric acid.
7. In a process .of treating uranium, the step of anodizing the surface of the uranium in a bath comprising a solution of approximately 50 percent by weight of phosphoric acid containing 20 to 100 cc. per liter of con-.
centrated hydrochloric acid.
8. In a process .of treating uranium, the steps of anodizing the surface of the unanium in a bath comprising a solution of approximately 20 to 60 percent by weight of phosphoric acid containing 20 to 100 cc. per liter of concentrated hydrochloric acid, and then dipping the I treated uranium shortly in nitric acid.
9. A process of treating a uranium surface comprising the steps of removing grease, removing oxide film by an acid dip, anodizing in a bath'containing from 20 to 60 percent by weight of phosphoric acid and from 20 to 100 cc. per liter of concentratedhydrochloric acid, removing the film resulting from anodizing and thereafter electroplating upon said surface.
References Cited inthefileof this patent UNITED STATES PATENTS 1,658,222 Burns Feb. 7, 1928 1,933,319 Driggs et a1. Oct. 31, 1933 2,133,255 Rogers Oct. 11, 1938' OTHER REFERENCES Transactions of the Electrochemical Society, vol. 66 (1934), pp. 40, 41.
Claims (1)
1. IN THE PROCESS OF ELECTROPLATING URANIUM, THE STEP OF ANODIZING THE SURFACE OF THE URANIUM IN A BATH COMPRISING A SOLUTION OF APPROXIMATELY 50 PERCENT BY WEIGHT OF PHOSPHORIC ACID CONTAINING ABOUT 20 CC. PER LITER OF CONCENTRATED HYDROCHLORIC ACID AT A TEMPERATURE OF ABOUT 35* TO 45* C. FOR APPROXIMATELY 10 MINUTES, THE ANODIZING CURRENT DENSITY BEING ABOUT 0.5 AMPERE PER SQUARE INCH OF SAID SURFACE.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US718623A US2872389A (en) | 1946-12-26 | 1946-12-26 | Treatment of uranium surfaces |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US718623A US2872389A (en) | 1946-12-26 | 1946-12-26 | Treatment of uranium surfaces |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2872389A true US2872389A (en) | 1959-02-03 |
Family
ID=24886810
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US718623A Expired - Lifetime US2872389A (en) | 1946-12-26 | 1946-12-26 | Treatment of uranium surfaces |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2872389A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3275535A (en) * | 1966-03-22 | 1966-09-27 | Jerry R Lundquist | Method of preparing uranium for nickel plating |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1658222A (en) * | 1925-02-10 | 1928-02-07 | Western Electric Co | Electrocleaning |
| US1933319A (en) * | 1930-07-26 | 1933-10-31 | Westinghouse Lamp Co | Electroplating tantalum |
| US2133255A (en) * | 1937-05-19 | 1938-10-11 | Percy A E Armstrong | Process of electroplating copper |
-
1946
- 1946-12-26 US US718623A patent/US2872389A/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1658222A (en) * | 1925-02-10 | 1928-02-07 | Western Electric Co | Electrocleaning |
| US1933319A (en) * | 1930-07-26 | 1933-10-31 | Westinghouse Lamp Co | Electroplating tantalum |
| US2133255A (en) * | 1937-05-19 | 1938-10-11 | Percy A E Armstrong | Process of electroplating copper |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3275535A (en) * | 1966-03-22 | 1966-09-27 | Jerry R Lundquist | Method of preparing uranium for nickel plating |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3664933A (en) | Process for acid copper plating of zinc | |
| JP4857340B2 (en) | Pretreatment of magnesium substrate for electroplating | |
| US5246565A (en) | High adherence copper plating process | |
| US3699013A (en) | Method of electroplating readily oxidizable metals | |
| EP0393169A1 (en) | Method for plating on titanium. | |
| US2835630A (en) | Treatment of metals prior to electro-plating | |
| US1971761A (en) | Protection of metals | |
| US2811484A (en) | Electrodeposition of zinc on magnesium and its alloys | |
| US2457059A (en) | Method for bonding a nickel electrodeposit to a nickel surface | |
| US2526544A (en) | Method of producing a metallic coating on magnesium and its alloys | |
| US2078868A (en) | Electroplating process | |
| US3531379A (en) | Process of coating aluminum with other metals | |
| US3207679A (en) | Method for electroplating on titanium | |
| US2511952A (en) | Process of plating zinc on aluminum | |
| US4450050A (en) | Process for bonding high efficiency chromium electrodeposits | |
| US2872389A (en) | Treatment of uranium surfaces | |
| US2739932A (en) | Electrodepositing chromium on aluminum | |
| US4196061A (en) | Direct nickel-plating of aluminum | |
| US2092130A (en) | Anodic cleaning process | |
| US2847371A (en) | Chromium plating on aluminum | |
| EP0010989B1 (en) | Method of plating aluminium | |
| US2966448A (en) | Methods of electroplating aluminum and alloys thereof | |
| US2729601A (en) | Electroplating on beryllium | |
| US3202589A (en) | Electroplating | |
| US2546150A (en) | Method for securing adhesion of electroplated coatings to a metal base |