US3334029A - Process for selectively anodically dissolving copper from zirconium - Google Patents
Process for selectively anodically dissolving copper from zirconium Download PDFInfo
- Publication number
- US3334029A US3334029A US262852A US26285263A US3334029A US 3334029 A US3334029 A US 3334029A US 262852 A US262852 A US 262852A US 26285263 A US26285263 A US 26285263A US 3334029 A US3334029 A US 3334029A
- Authority
- US
- United States
- Prior art keywords
- copper
- zirconium
- covering
- article
- dissolution
- 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
- 238000000034 method Methods 0.000 title claims description 12
- 230000008569 process Effects 0.000 title claims description 12
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 title claims description 9
- 229910052726 zirconium Inorganic materials 0.000 title claims description 9
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 title description 14
- 229910052802 copper Inorganic materials 0.000 title description 14
- 239000010949 copper Substances 0.000 title description 14
- 238000004090 dissolution Methods 0.000 claims description 20
- 238000005868 electrolysis reaction Methods 0.000 claims description 10
- 229910045601 alloy Inorganic materials 0.000 claims description 8
- 239000000956 alloy Substances 0.000 claims description 8
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 5
- 238000007743 anodising Methods 0.000 claims description 5
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 claims description 5
- 235000011149 sulphuric acid Nutrition 0.000 claims description 5
- 239000001117 sulphuric acid Substances 0.000 claims description 5
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 claims description 4
- -1 SULPHATE IONS Chemical class 0.000 claims description 4
- 229910001431 copper ion Inorganic materials 0.000 claims description 4
- 229910021653 sulphate ion Inorganic materials 0.000 claims description 4
- 239000003792 electrolyte Substances 0.000 description 14
- 229910052751 metal Inorganic materials 0.000 description 14
- 239000002184 metal Substances 0.000 description 14
- 239000003517 fume Substances 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 229910052770 Uranium Inorganic materials 0.000 description 2
- 229910001093 Zr alloy Inorganic materials 0.000 description 2
- 238000000137 annealing Methods 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 239000008151 electrolyte solution Substances 0.000 description 2
- 230000008030 elimination Effects 0.000 description 2
- 238000003379 elimination reaction Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 description 2
- RZVAJINKPMORJF-UHFFFAOYSA-N Acetaminophen Chemical compound CC(=O)NC1=CC=C(O)C=C1 RZVAJINKPMORJF-UHFFFAOYSA-N 0.000 description 1
- 229910000711 U alloy Inorganic materials 0.000 description 1
- HXPJIEMQFBIQMQ-UHFFFAOYSA-N [Zr].[U] Chemical compound [Zr].[U] HXPJIEMQFBIQMQ-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000012042 active reagent Substances 0.000 description 1
- 239000010407 anodic oxide Substances 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 150000001879 copper Chemical class 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 238000001192 hot extrusion Methods 0.000 description 1
- 239000013067 intermediate product Substances 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 230000001473 noxious effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 150000003754 zirconium Chemical class 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
- C25F5/00—Electrolytic stripping of metallic layers or coatings
Definitions
- the present invention relates to a process for the selective anodic dissolution of a metal coating.
- Elimination of the protective covering, when the deformation operations are completed, can be effected 'by mechanical means, but most often this elimination is either very costly or incomplete, because of intermetallic penetration which can take place between the covering and the article itself.
- the process of selective anodic dissolution of a metallic coating accordingto the invention does not have the disadvantages mentioned above.
- the protected part with its metallic covering is treated electrolytically as an anode, by utilising a rapid-action electrolyte of a composition which is substantially independent of the duration of the operation of the dissolution, the metal which is to be uncovered not being attacked by the electrolyte or being covered by a barrier layer under selected conditions for the transfer of the covering metal.
- a selective electrolytic dissolution process comprises anodising an article comprising zirconium or a zirconium-base alloy having a covering of copper or a copper-base alloy in an electrolyte containing copper ions and sulphate ions.
- the electrolyte contains 25 to 100 g./l. of sulphuric acid and 50 to 100 g./l. of copper sulphate.
- the electrolysis potential is from 0.5 to v.
- cathodic current density is from 0.2 to 15 a./sq. dm. and the cathode-to-anode surface ratio is from 0.1 to 10.
- the example relates to the anodic dissolution of a copper covering plate-d on to an article of zirconium or an alloy of zirconium with other metals such as uranium.
- the copper covering which has been applied to the article by a hot extrusion operation, followed if desired by working in the cold or at moderate temperature and annealing in air, is to be removed so that the article itself can be subjected to finishing operations which impart to it the dimensional tolerances and surface state desired.
- dissolution of the covering is carried out chemically in fluoro-nitric baths or nitric baths which cause the evolution of noxious vapours which must be trapped, neutrilsed and scrubbed.
- the bath becomes loaded with copper salts and zirconium salts, which necessitates an expensive chemical recovery process.
- the application of the invention to this particular case consists in effecting the dissolution of the copper covering by anodising, viz, electrolysis as an anode, under the following conditions.
- the metallic part surrounded by its covering which is to be dissolved away constitutes the anode of the electrolytic cell used.
- the cathode is constituted by grids of wires or expanded metal located above and below the anode at a minimum distance of 5 mm.
- the temperature of the electrolysis bath should be from 2030 C.
- the potential applied between the anode and the cathode is maintained at a value of from 0.5 to 6 volts, the cathodic current density being from 0.5 to 1 a./dm.
- the speed of dissolution of the copper of the covering constituting the anode is about 1 g. per amp. per hour, the copper being transferred to the cathode where it deposits in a compact form.
- the thickness of the copper covering diminishes by mm. per lamp. per drn. (current density) per hour.
- an anodic oxide layer forms which has a thickness of less than 0.1 micron at the temperature and potential and in the electrolyte indicated. It is the same if the anode is of zirconium.
- the copper which has diffused at the covering/article interface is entirely.
- the electrolyte Even in the case where electrolysis is carried out for a long time after complete dissolution of the copper, the electrolyte only contains low quantities of zirconiurn and there is zirconium alloyed with copp r in the interditfusion layer which may be formed.
- the article is of a zirconium-uranium alloy, the manium content of which is less than 6%, the same electrolyte even after prolonged operation only contains very small quantities of uranium, corresponding to an interdiifusion layer formed between the copper and zirconiumuranium alloy.
- the electrolyte does not undergo any modification of composition and is always ready for use and requires virtually the minimum of maintenance.
- the electrolyte can be agitated if desired or not.
- the copper deposited on the cathode can be recovered directly in the metallic state.
- the process which has been described can be applied to metallic parts which have various different shapes. If the process is applied to an article of great length, this is placed in an electrolytic bath, rolled in a spirial with spacers giving distances of 10-20 mm. between adjacent turns When the article coated with the covering has a tubular or hollow form, an auxiliary cathode is used which penerta-tes into the re-entrant part.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electrolytic Production Of Metals (AREA)
- Electroplating And Plating Baths Therefor (AREA)
Description
United States Patent Office 2 Claims. (61. 204-32 The present invention, relates to a process for the selective anodic dissolution of a metal coating.
It is common practice for a metal article or an intermediate product which is sensitive to the air to be surrounded by a continuous sealed sheath or covering, before being subjected to shaping operations. This protective covering protects the central part against changes due to the air, at temperatures to which it is taken either during deformation to which it is subjected by forging, drawing or laminating or during annealing operations which precede deformation operations carried out in the cold or between such operations.
It is also advantageous to provide such a covering to insulate such a part when it is desired to facilitate lubrication, during deformation steps, in order to avoid any contamination due to friction between the machined surfaces.
Elimination of the protective covering, when the deformation operations are completed, can be effected 'by mechanical means, but most often this elimination is either very costly or incomplete, because of intermetallic penetration which can take place between the covering and the article itself.
It is preferable, therefore, to make use of chemical dissolution, but the use of the active reagents currently utilised has certain disadvantages:
(a) Production of vapours of fumes, which require complicated and troublesome trapping arrangements and neutralisations;
(b) Partial dissolution of the metal of the covering, the reagent eliminating the products of interpenetration due to interdiffusion phenomena between the two metals;
(c) If the covering does not have uniform thickness, in general, dissolution of the article begins when it has become bared and continues until the metal of the covering has completely disappeared;
(d) In the case where the protected part is constituted by a metal of high cost, dissolution of a certain quantity of this metal involves an exorbitant loss as such dissolution can present certain dangers which absolutely prohibit it.
The process of selective anodic dissolution of a metallic coating accordingto the invention does not have the disadvantages mentioned above. In essence, the protected part with its metallic covering is treated electrolytically as an anode, by utilising a rapid-action electrolyte of a composition which is substantially independent of the duration of the operation of the dissolution, the metal which is to be uncovered not being attacked by the electrolyte or being covered by a barrier layer under selected conditions for the transfer of the covering metal.
According to the invention, a selective electrolytic dissolution process is provided, which comprises anodising an article comprising zirconium or a zirconium-base alloy having a covering of copper or a copper-base alloy in an electrolyte containing copper ions and sulphate ions.
Preferably, the electrolyte contains 25 to 100 g./l. of sulphuric acid and 50 to 100 g./l. of copper sulphate.
,In a preferred embodiment of the process of the invention, the electrolysis potential is from 0.5 to v., the
3,334,029 Patented Aug. 1, 1967 cathodic current density is from 0.2 to 15 a./sq. dm. and the cathode-to-anode surface ratio is from 0.1 to 10.
The process of the invention has several advantages:
(1) It is rapid;
(2) It is practical, because the anodic dissolution stops automatically over all regions where the article has been uncovered, as the metal of the covering fixed to the article by superficial ditfusion is dissolved;
(3) The electrolyte does not evolve any fumes during or after its period of activity;
(4) The action of the electrolyte is constant, even when the protective metal has not been uncovered;
(5) It is economical, because it does not require frequent bath changes and only causes a very slight dissolution of the bared metal.
A preferred embodiment of the process according to the invention is described below by way of example, it being understood that this embodiment is given only by way of example.
The example relates to the anodic dissolution of a copper covering plate-d on to an article of zirconium or an alloy of zirconium with other metals such as uranium. The copper covering, which has been applied to the article by a hot extrusion operation, followed if desired by working in the cold or at moderate temperature and annealing in air, is to be removed so that the article itself can be subjected to finishing operations which impart to it the dimensional tolerances and surface state desired.
At present, dissolution of the covering is carried out chemically in fluoro-nitric baths or nitric baths which cause the evolution of noxious vapours which must be trapped, neutrilsed and scrubbed. The bath becomes loaded with copper salts and zirconium salts, which necessitates an expensive chemical recovery process.
The application of the invention to this particular case consists in effecting the dissolution of the copper covering by anodising, viz, electrolysis as an anode, under the following conditions.
The metallic part surrounded by its covering which is to be dissolved away constitutes the anode of the electrolytic cell used. The cathode is constituted by grids of wires or expanded metal located above and below the anode at a minimum distance of 5 mm.
The electrolyte is a solution of 100 g. per litre of copper sulphate containing 50 g. per litre of sulphuric acid at 66 B. (sp. gr.=1.83).
The temperature of the electrolysis bath should be from 2030 C.
The potential applied between the anode and the cathode is maintained at a value of from 0.5 to 6 volts, the cathodic current density being from 0.5 to 1 a./dm.
in the case where the bath is not agitated.
Under these conditions, the speed of dissolution of the copper of the covering constituting the anode is about 1 g. per amp. per hour, the copper being transferred to the cathode where it deposits in a compact form. The thickness of the copper covering diminishes by mm. per lamp. per drn. (current density) per hour.
When the zirconium alloy article comes into contact with the electrolyte, an anodic oxide layer forms which has a thickness of less than 0.1 micron at the temperature and potential and in the electrolyte indicated. It is the same if the anode is of zirconium. The copper which has diffused at the covering/article interface is entirely.
dissolved. Even in the case where electrolysis is carried out for a long time after complete dissolution of the copper, the electrolyte only contains low quantities of zirconiurn and there is zirconium alloyed with copp r in the interditfusion layer which may be formed.
If the article is of a zirconium-uranium alloy, the manium content of which is less than 6%, the same electrolyte even after prolonged operation only contains very small quantities of uranium, corresponding to an interdiifusion layer formed between the copper and zirconiumuranium alloy.
The operation of electrolysis does not involve the evolution of fumes or vapours. When the surface of the article has oxide points with sharp corners or plates which are more or less encrusted, these can become detached :at the end of the dissolution. They fall to the bottom of the bath without becoming dissolved in the electrolyte.
The electrolyte does not undergo any modification of composition and is always ready for use and requires virtually the minimum of maintenance. The electrolyte can be agitated if desired or not. The copper deposited on the cathode can be recovered directly in the metallic state.
The process which has been described can be applied to metallic parts which have various different shapes. If the process is applied to an article of great length, this is placed in an electrolytic bath, rolled in a spirial with spacers giving distances of 10-20 mm. between adjacent turns When the article coated with the covering has a tubular or hollow form, an auxiliary cathode is used which penerta-tes into the re-entrant part.
What we claim is:
1. In a selective electrolytic dissolution process, the step of anodising an article of zirconium or a zirconiumbase alloy having a substantially continuous covering of copper or a copper-base alloy in an electrolyte solution of copper ions and sulphate ions having 25-100 g./l. of sulphuric acid and from -200 g./l. of copper sulphate, in which the electrolysis potential is from 0.5 to 10 v., in which the cathodic current density is from 0.2 to 15 a./dm. and in which the cathode-to-anode surface ratio is from 0.1 to 10.
2. In a selective electrolytic dissolution process, the step of anodising an article of zirconium or a zirconiumbase alloy having a substantially continuous covering of copper or a copper-base alloy in an electrolyte solution of copper ions and sulphate ions having 50 g./ l. of sulphuric acid and g./l. of copper sulphate, in which the electrolysis potential is from 0.5 to 6 v., in which the current-density is from 0.5 to l a./dm. in which the electrolysis temperature is from 20 to 30 C. and in which the cathode-to-anode surface ratio is from 0.1 to 10.
References Cited UNITED STATES PATENTS 2,196,133 4/1940 Webb i 204l46 3,063,917 11/1962 Barto 204l46 X OTHER REFERENCES Miller, Zirconium, Academic Press, Inc., publishers, New York, 1954, page 203.
JOHN H. MACK, Primary Examiner.
ROBERT K. MIHALEK, Examiner.
Claims (1)
- 2. IN A SELECTIVE ELECTROLYTIC DISSOLUTION PROCESS, THE STEP OF ANODISING AN ARTICLE OF ZIRCONIUM OR A ZIRCONIUMBASE ALLOY HAVING A SUBSTANTIALLY CONTINOUS COVERING OF COPPER OR A COPPER-BASE ALLOY IN AN ELECTRLYTE SOLUTION OF COPPER IONS AND SULPHATE IONS HAVING 50 G./1. OF SULPHURIC ACID AND 100 G./1. OF COPPER SULPHATE, IN WHICH THE ELECTROLYSIS POTENTIAL IS FROM 0.5 TO 6 V., IN WHICH THE CURRENT-DENSITY IS FROM 0.5 TO 1 A./DM.2 IN WHICH THE ELECTROLYSIS TEMPERATURE IS FROM 20* TO 30*C. AND IN WHICH THE CATHODE-TO-ANODE SURFACE RATIO IS FROM 0.1 TO 10.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR891708A FR1327768A (en) | 1962-03-21 | 1962-03-21 | Method of selective anodic dissolution of a metallic coating |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3334029A true US3334029A (en) | 1967-08-01 |
Family
ID=8774973
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US262852A Expired - Lifetime US3334029A (en) | 1962-03-21 | 1963-03-05 | Process for selectively anodically dissolving copper from zirconium |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US3334029A (en) |
| BE (1) | BE629890A (en) |
| DE (1) | DE1195132B (en) |
| FR (1) | FR1327768A (en) |
| GB (1) | GB1032293A (en) |
| LU (1) | LU43371A1 (en) |
| NL (1) | NL290090A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0415130A1 (en) * | 1989-08-31 | 1991-03-06 | Led Italia S.R.L. | Method to eliminate the filling in wrought hollow gold and wrought hollow gold thus processed |
| US5250507A (en) * | 1990-08-17 | 1993-10-05 | Hoechst Aktiengesellschaft | Process for producing molded bodies from precursors of oxidic high-temperature superconductors |
| US20130220530A1 (en) * | 2012-02-24 | 2013-08-29 | Kuanping Gong | Method of transferring graphene |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE1001539A3 (en) * | 1988-03-17 | 1989-11-21 | Bekaert Sa Nv | Metal fibers obtained by bundled PULLING. |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2196133A (en) * | 1936-09-28 | 1940-04-02 | Robert Laing Bruce Gall | Photography |
| US3063917A (en) * | 1959-06-29 | 1962-11-13 | Combustion Eng | Anodic decontamination of zirconium and hafnium |
-
0
- BE BE629890D patent/BE629890A/xx unknown
- NL NL290090D patent/NL290090A/xx unknown
-
1962
- 1962-03-21 FR FR891708A patent/FR1327768A/en not_active Expired
-
1963
- 1963-03-05 US US262852A patent/US3334029A/en not_active Expired - Lifetime
- 1963-03-07 DE DEC29323A patent/DE1195132B/en active Pending
- 1963-03-14 GB GB10196/63A patent/GB1032293A/en not_active Expired
- 1963-03-16 LU LU43371D patent/LU43371A1/xx unknown
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2196133A (en) * | 1936-09-28 | 1940-04-02 | Robert Laing Bruce Gall | Photography |
| US3063917A (en) * | 1959-06-29 | 1962-11-13 | Combustion Eng | Anodic decontamination of zirconium and hafnium |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0415130A1 (en) * | 1989-08-31 | 1991-03-06 | Led Italia S.R.L. | Method to eliminate the filling in wrought hollow gold and wrought hollow gold thus processed |
| US5250507A (en) * | 1990-08-17 | 1993-10-05 | Hoechst Aktiengesellschaft | Process for producing molded bodies from precursors of oxidic high-temperature superconductors |
| US20130220530A1 (en) * | 2012-02-24 | 2013-08-29 | Kuanping Gong | Method of transferring graphene |
| US9039886B2 (en) * | 2012-02-24 | 2015-05-26 | Cheil Industries, Inc. | Method of transferring graphene |
Also Published As
| Publication number | Publication date |
|---|---|
| BE629890A (en) | |
| DE1195132B (en) | 1965-06-16 |
| GB1032293A (en) | 1966-06-08 |
| LU43371A1 (en) | 1963-05-16 |
| NL290090A (en) | |
| FR1327768A (en) | 1963-05-24 |
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