EP0139958B1 - Process for electrolytically polishing a work piece made of a nickel, cobalt or iron based alloy - Google Patents

Process for electrolytically polishing a work piece made of a nickel, cobalt or iron based alloy Download PDF

Info

Publication number
EP0139958B1
EP0139958B1 EP84109758A EP84109758A EP0139958B1 EP 0139958 B1 EP0139958 B1 EP 0139958B1 EP 84109758 A EP84109758 A EP 84109758A EP 84109758 A EP84109758 A EP 84109758A EP 0139958 B1 EP0139958 B1 EP 0139958B1
Authority
EP
European Patent Office
Prior art keywords
volume
concentrated
vol
fluorosurfactant
electrolyte
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
Application number
EP84109758A
Other languages
German (de)
French (fr)
Other versions
EP0139958A1 (en
Inventor
Vladimir Sova
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BBC Brown Boveri AG Switzerland
Original Assignee
BBC Brown Boveri AG Switzerland
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by BBC Brown Boveri AG Switzerland filed Critical BBC Brown Boveri AG Switzerland
Publication of EP0139958A1 publication Critical patent/EP0139958A1/en
Application granted granted Critical
Publication of EP0139958B1 publication Critical patent/EP0139958B1/en
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F3/00—Electrolytic etching or polishing
    • C25F3/16—Polishing
    • C25F3/22—Polishing of heavy metals

Definitions

  • the invention is based on a method for the electrolytic polishing of a workpiece made of an alloy based on nickel, cobalt or iron, according to the preamble of claim 1.
  • electrolytes based on concentrated acids such as sulfuric acid, phosphoric acid and nitric acid are mostly used. Due to the action of the acids mentioned, a preferred removal of surface roughness should occur during the anodic treatment of the metal objects. If the working conditions are set appropriately, this removal can lead to the surface shining.
  • Various theories were elaborated to clarify the electropolishing processes. Usually there are considerations about the physical properties of the electrolyte. The viscosity of the electrolyte plays an important role here with regard to the diffusion processes at the anode. Another factor is the influence of conductivity on the current-voltage ratio.
  • the electrolytic polishing of stainless steels is known, inter alia, from DE-PS 938 402, DE-PS 754 703, DE-AS 1 913 570, US-PS 3 751 352.
  • the corresponding method for superalloys is e.g. described in DE-OS 26 54 484.
  • the reason for this is the uneven dissolution of all metals involved or even the concentration of the poorly soluble components on the treated surface.
  • the perchloric acid-based electrolyte has brought about very good electropolishing effects, but from a practical point of view such an electrolyte cannot be used in production.
  • the required operating temperature is too low for this and there is a risk of later corrosive attack due to degraded chloride ions.
  • the invention has for its object to provide a method for the electrolytic polishing of a workpiece made of a nickel, cobalt or iron alloy, in particular superalloy, which provides clean, shiny workpiece surfaces and can be carried out under normal workshop conditions and in indoor and outdoor temperatures without risk of explosion .
  • the corresponding electrolyte should have a long usability.
  • a gas turbine blade made of a nickel superalloy with the trade name Nimonic was electrolytically polished as the workpiece.
  • the workpiece was first degreased in organic solvents and then placed in a suitable hooking device (frame).
  • the frame was hung with the workpiece as an anode in the electrolysis bath and a cell voltage of 50 V was set.
  • Electrolytically polishing was then carried out for 3 minutes at a current density of 80 A / dm 2 and a temperature of 0 ° C. After the polishing process was completed, the power was switched off, the workpiece with the frame was removed from the bath and rinsed several times in cold and warm water.
  • the workpiece was then dried in a hot air stream at a temperature of 80 to 90 ° C. After removal from the rack and cooling the workpiece showed a glossy, reflective surface at room temperature.
  • the workpiece consisted of a nickel-based superalloy with the trade name Hastelloy. Before electrolytic polishing, it was degreased in organic solvents (trichlorethylene, perchlorethylene) and then hung in a device similar to that described in Example 1. The whole was immersed in the above-mentioned electrolysis bath, where it served as an anode. The cell voltage was set to 20 V and electrolytically polished for 5 min. The further treatment of the workpiece, rinsing, drying, etc. was carried out in the manner given in Example 1.
  • Example 1 A component made of an austenitic iron alloy of the type X10CrNiW 17/13 was used as the workpiece. It was first degreased in organic solvents and then installed in a suitable rack. The procedure of Example 1 was also followed. The cell voltage was kept at 70 V during the electrolytic polishing. The polishing time was 7 min. The workpiece was then treated in the manner specified in Example 1.
  • the invention is not restricted to the exemplary embodiment.
  • the process is basically applicable to Ni, Co or Fe-based alloys - mainly austenitic materials.
  • the electrolyte which is usually built on a concentrated non-oxidizing acid such as H 2 S0 4 or H 3 P0 4 and also contains a fluorosurfactant and a weak polar organic compound, is converted into a fluorine compound in the form of a simple or complex fluoride in an amount of at least 2 vol. -% beige quantity.
  • the content of concentrated H 2 S0 4 or H 3 P0 4 can be between 20 and 80 vol .-%. If both of the aforementioned acids were used at the same time, their content would advantageously be 10 to 40% by volume.
  • the electrolyte may also contain 10 to 30% by volume of C 2 H 5 OH and 2-propanol. Approximately 0.2% by volume of a fluorosurfactant is added to the electrolyte throughout.
  • the electrolytic polishing is advantageously carried out at temperatures between -20 and +30 ° C at anodic current densities of 20 to 250 A / dm 2 under cell voltages of 20 to 70 V for 20 sec to 20 min.

Description

Die Erfindung geht aus von einem Verfahren zum elektrolytischen Polieren eines Werkstücks aus einer Legierung auf Nickel-, Kobalt- oder Eisenbasis nach der Gattung des Oberbegriffs des Anspruchs 1.The invention is based on a method for the electrolytic polishing of a workpiece made of an alloy based on nickel, cobalt or iron, according to the preamble of claim 1.

Beim elektrolytischen Polieren von Metallen und Legierungen der Gruppen IVB, VB, VIB und VIII des periodischen Systems der Elemente werden meistens Elektrolyte auf der Basis konzentrierter Säuren wie Schwefelsäure, Phosphorsäure und Salpetersäure eingesetzt. Durch die Wirkung der erwähnten Säuren sollte bei der anodischen Behandlung der Metallgegenstände eine bevorzugte Abtragung von Oberflächenrauheiten zustandekommen. Diese Abtragung kann bei geeigneter Einstellung der Arbeitsbedingungen bis zum Glänzen der Oberfläche führen. Zur Abklärung der Elektropoliervorgänge wurden verschiedene Theorien ausgearbeitet. Meistens sind es Ueberlegungen über physikalische Eigenschaften des Elektrolyten. Hier spielt eine wichtige Rolle die Viskosität des Elektrolyten hinsichtlich der Diffusionsvorgänge an der Anode. Ein anderer Faktor ist der Einfluss der Leitfähigkeit bezüglich des Strom-Spannungsverhältnisses.In the electrolytic polishing of metals and alloys of groups IVB, VB, VIB and VIII of the periodic system of the elements, electrolytes based on concentrated acids such as sulfuric acid, phosphoric acid and nitric acid are mostly used. Due to the action of the acids mentioned, a preferred removal of surface roughness should occur during the anodic treatment of the metal objects. If the working conditions are set appropriately, this removal can lead to the surface shining. Various theories were elaborated to clarify the electropolishing processes. Mostly there are considerations about the physical properties of the electrolyte. The viscosity of the electrolyte plays an important role here with regard to the diffusion processes at the anode. Another factor is the influence of conductivity on the current-voltage ratio.

Das elektrolytische Polieren rostfreier Stähle ist unter anderem bekannt aus der DE-PS 938 402, DE-PS 754 703, DE-AS 1 913 570, US-PS 3 751 352. Das entsprechende Verfahren für Superlegierungen ist z.B. in der DE-OS 26 54 484 beschrieben.The electrolytic polishing of stainless steels is known, inter alia, from DE-PS 938 402, DE-PS 754 703, DE-AS 1 913 570, US-PS 3 751 352. The corresponding method for superalloys is e.g. described in DE-OS 26 54 484.

Beim elektrolytischen Polieren sind hauptsächlich zwei gleichzeitig zu bewerkstellende Prozesse zu beachten: Die Einebnung der Oberfläche, d.h. die bevorzugte Auflösung der makro- bis mikroskopisch vorliegenden Rauheiten der Oberfläche, ohne dass dabei ein Kornangriff in die Tiefe erfolgt, sowie die Auflösung der gebildeten Metalloxydschicht an der Oberfläche. Bei der Behandlung von Legierungen kommt noch ein dritter, wichtiger Faktor zum Zuge, die gleichmässige Auflösung von allen beteiligten Metallkomponenten. Diese gleichmässige Auflösung von allen in der Legierung vorhandenen Metallen ist umso schwieriger, je mehr die Metalle aus verschiedenen Gruppen des periodischen Systems der Elemente stammen. Bei sehr komplex zusammengesetzten Legierungen des Nickelbasis-Typs (beispielsweise Superlegierungen wie die "Nimonics") konnte zwar mit herkömmlichen Mitteln ein elektrolytischer Poliereffekt erreicht werden, doch blieb die Oberfläche stumpf und matt. Der Grund dafür ist die ungleichmässige Auflösung aller beteiligten Metalle oder sogar die Aufkonzentrierung der schwerlöslichen Komponenten an der behandelten Oberfläche. Der Elektrolyt auf Perchlorsäurebasis hat zwar sehr gute Elektropolierwirkung gebracht, aber aus der praktischen Sicht ist ein solcher Elektrolyt in der Produktion nicht verwendbar. Dazu ist die erforderliche Betriebstemperatur zu tief und es besteht die Gefahr des späteren korrosiven Angriffs durch abgebaute Chloridionen. Ausserdem besteht bei diesem Verfahren Explosionsgefahr und die Verwendungszeit (Lebensdauer) der Elektrolyten ist zu kurz.With electrolytic polishing, there are two main processes to be considered at the same time: the preferred resolution of the macro- to microscopic roughness of the surface without any grain attack in depth, and the resolution of the metal oxide layer formed on the surface. When treating alloys, a third, important factor comes into play: the uniform dissolution of all metal components involved. This uniform dissolution of all metals present in the alloy is more difficult the more the metals come from different groups in the periodic system of the elements. In the case of very complex alloys of the nickel-based type (for example superalloys such as "Nimonics"), an electrolytic polishing effect could be achieved using conventional means, but the surface remained dull and matt. The reason for this is the uneven dissolution of all metals involved or even the concentration of the poorly soluble components on the treated surface. The perchloric acid-based electrolyte has brought about very good electropolishing effects, but from a practical point of view such an electrolyte cannot be used in production. The required operating temperature is too low for this and there is a risk of later corrosive attack due to degraded chloride ions. In addition, there is a risk of explosion with this method and the usage time (service life) of the electrolytes is too short.

Es besteht daher ein Bedürfnis nach der Verbesserung der konventionellen Verfahren des elektrolytischen Polierens. Der Erfindung liegt die Aufgabe zugrunde, ein Verfahren zum elektrolytischen Polieren eines Werkstücks aus einer Nickel-, Kobalt- oder Eisenlegierung, insbesondere Superlegierung anzugeben, das saubere, glänzende Werkstückoberflachen liefert und ohne Explosionsgefahr unter normalen Werkstattbedingungen sowie im Raum und im Freien vorkommenden Temperaturen durchführbar ist. Der entsprechende Elektrolyt soll dabei eine möglichst lange Verwendbarkeit aufweisen.There is therefore a need to improve conventional electrolytic polishing processes. The invention has for its object to provide a method for the electrolytic polishing of a workpiece made of a nickel, cobalt or iron alloy, in particular superalloy, which provides clean, shiny workpiece surfaces and can be carried out under normal workshop conditions and in indoor and outdoor temperatures without risk of explosion . The corresponding electrolyte should have a long usability.

Diese Aufgabe wird durch die im kennzeichnenden Teil des Anspruchs 1 angegebenen Merkmale gelöst. Die Erfindung wird anhand der nachfolgenden Ausführungsbeispiele näher beschrieben.This object is achieved by the features specified in the characterizing part of claim 1. The invention is described in more detail using the following exemplary embodiments.

Ausführungsbeispiel 1:Example 1:

Zur Herstellung des Elektrolysebades wurden zunächst 6 Volumenteile konzentrierte H2S04 mit 2 Volumenteilen C2H50H gemischt. Dann wurde 1 Volumenteil HBF4 beigemischt. Zuletzt wurden noch 1 Volumenteil Glyzerin und 0,1 Vol.-% eines Fluorotensids zugegeben. Danach wurde das Bad auf die Arbeitstemperatur von 0 °C abgekühlt.To produce the electrolysis bath, 6 parts by volume of concentrated H 2 S0 4 were first mixed with 2 parts by volume of C 2 H 5 0H. Then 1 volume part of HBF 4 was added. Finally, 1 volume part of glycerin and 0.1 volume% of a fluorosurfactant were added. The bath was then cooled to the working temperature of 0 ° C.

Das fertige Elektrolysebad hatte ungefähr folgende Zusammensetzung:

  • Konzentrierte H2S04: 60 Vol.-%
  • C2H5OH: 20 Vol.-%
  • Glyzerin: 10 Vol.-%
  • HBF4: 10 Vol.-%
  • Fluorotensid: 0,1 Vol.-%
The finished electrolysis bath had approximately the following composition:
  • Concentrated H 2 S0 4 : 60 vol .-%
  • C 2 H 5 OH: 20 vol.%
  • Glycerin: 10 vol .-%
  • HBF 4 : 10% by volume
  • Fluorosurfactant: 0.1% by volume

Als Werkstück wurde eine Gasturbinenschaufel aus einer Nickel-Superlegierung mit dem Handelsnamen Nimonic elektrolytisch poliert. Das Werkstück wurde zunächst in organischen Lösungsmitteln entfettet und dann in eine geeignete Einhängevorrichtung (Gestell) gebracht. Das Gestell wurde mit dem Werkstück als Anode in das Elektrolysebad eingehängt und eine Zellenspannung von 50 V eingestellt. Nun wurde während 3 min bei einer Stromdichte von 80 A/dm2 etwa einer Temperatur von 0 ° C elektrolytisch poliert. Nach Abschluss des Poliervorganges wurde der Strom abgeschaltet, das Werkstück mit Gestell aus dem Bad herausgenommen und mehrmals in kaltem und warmem Wasser gespült. Dann wurde das Werkstück im Warmluftstrom bei einer Temperatur von 80 bis 90 °C getrocknet. Nach der Entfernung aus dem Gestell und der Abkühlung auf Raumtemperatur zeigte das Werkstück eine glänzende spiegelnde Oberfläche.A gas turbine blade made of a nickel superalloy with the trade name Nimonic was electrolytically polished as the workpiece. The workpiece was first degreased in organic solvents and then placed in a suitable hooking device (frame). The frame was hung with the workpiece as an anode in the electrolysis bath and a cell voltage of 50 V was set. Electrolytically polishing was then carried out for 3 minutes at a current density of 80 A / dm 2 and a temperature of 0 ° C. After the polishing process was completed, the power was switched off, the workpiece with the frame was removed from the bath and rinsed several times in cold and warm water. The workpiece was then dried in a hot air stream at a temperature of 80 to 90 ° C. After removal from the rack and cooling the workpiece showed a glossy, reflective surface at room temperature.

Ausführungsbeispiel 11:Example 11:

Zunächst wurden zur Zubereitung des Elektrolysebades 3 Volumenteile konzentrierte H3P04 mit 5 Volumenteilen C2HsOH und 1 Volumenteil Glyzerin sowie 1 Volumenteil Ammoniumdifluorid inkl. 0,1 Vol.-% Fluorotensid gemischt. Das Bad wurde auf eine Arbeitstemperatur von -10 ° C abgekühlt. Das fertige Elektrolysebad hatte ungefähr folgende Zusammensetzung:

  • Konzentrierte H3P04: 30 Vol.-%
  • C2H5OH: 50 Vol.-%
  • Glyzerin: 10 Vol.-%
  • Ammoniumdifluorid: 10 Vol.-%
  • Fluorotensid: 0,1 Vol.-%
First, to prepare the electrolysis bath, 3 parts by volume of concentrated H 3 P0 4 were mixed with 5 parts by volume of C 2 H s OH and 1 part by volume of glycerin and 1 part by volume of ammonium difluoride including 0.1% by volume of fluorosurfactant. The bath was cooled to a working temperature of -10 ° C. The finished electrolysis bath had approximately the following composition:
  • Concentrated H 3 P0 4 : 30 vol .-%
  • C 2 H 5 OH: 50 vol.%
  • Glycerin: 10 vol .-%
  • Ammonium difluoride: 10 vol .-%
  • Fluorosurfactant: 0.1% by volume

Das Werkstück bestand aus einer Nickelbasis-Superlegierung mit dem Handelsnamen Hastelloy. Vor dem elektrolytischen Polieren wurde es in organischen Lösungsmitteln (Trichloräthylen, Perchloräthylen) entfettet und dann in eine Vorrichtung ähnlich wie unter Beispiel 1 beschrieben, eingehängt. Das Ganze wurde in das oben angegebene Elektrolysebad eingetaucht, wo es als Anode diente. Die Zellenspannung wurde auf den Wert 20 V eingestellt und während 5 min elektrolytisch poliert. Die Weiterbehandlung des Werkstücks, das Spülen, Trocknen etc. erfolgte in der unter Beispiel 1 angegebenen Weise.The workpiece consisted of a nickel-based superalloy with the trade name Hastelloy. Before electrolytic polishing, it was degreased in organic solvents (trichlorethylene, perchlorethylene) and then hung in a device similar to that described in Example 1. The whole was immersed in the above-mentioned electrolysis bath, where it served as an anode. The cell voltage was set to 20 V and electrolytically polished for 5 min. The further treatment of the workpiece, rinsing, drying, etc. was carried out in the manner given in Example 1.

Ausführungsbeispiel IIIEmbodiment III

Zur Herstellung des Elektrolysebades wurden 2 Volumenteile konzentrierte H3PO4 und 2 Volumenteile konzentrierte H2S04 mit 2 Volumenteilen C2H5OH und 2 Teilen 2-Propanol gemischt. Ausserdem wurde eine Lösung von 1 Volumenteil Natriumfluosilikat und 1 Volumenteil HF inkl. 0,1 Vol.-% eines Fluorotensids hergestellt und der ersten Mischung beigegeben. Das auf diese Weise hergestellte Bad wurde auf eine Arbeitstemperatur von 12 °C gebracht.To produce the electrolysis bath, 2 parts by volume of concentrated H 3 PO 4 and 2 parts by volume of concentrated H 2 SO 4 were mixed with 2 parts by volume of C 2 H 5 OH and 2 parts of 2-propanol. In addition, a solution of 1 volume of sodium fluorosilicate and 1 volume of HF including 0.1% by volume of a fluorosurfactant was prepared and added to the first mixture. The bath prepared in this way was brought to a working temperature of 12 ° C.

Das fertige Elektrolysebad hatte demgemäss ungefähr folgende Zusammensetzung:

  • konzentrierte H3P04: 20 Vol.-%
  • konzentrierte H2S04: 20 Vol.-%
  • C2HsOH: 20 Vol.-%
  • 2-Propanol: 20 Vol.-%
  • HF: 10 Vol.-%
  • Natriumfluosilikat: 10 Vol.-%
  • Fluorotensid: 0,1 Vol.-%
The finished electrolysis bath therefore had approximately the following composition:
  • concentrated H 3 P0 4 : 20 vol .-%
  • concentrated H 2 S0 4 : 20 vol.%
  • C 2 H s OH: 20 vol.%
  • 2-propanol: 20 vol.%
  • HF: 10 vol.%
  • Sodium fluorosilicate: 10% by volume
  • Fluorosurfactant: 0.1% by volume

Als Werkstück wurde ein Bauteil aus einer austenitischen Eisenlegierung des Typs X10CrNiW 17/13 verwendet. Es wurde zunächst in organischen Lösungsmitteln entfettet und dann in ein geeignetes Gestell eingebaut. Des weiteren wurde gemäss Beispiel 1 verfahren. Die Zellenspannung während des elektrolytischen Polierens wurde auf 70 V gehalten. Die Dauer des Polierens betrug 7 min. Die Behandlung des Werkstücks erfolgte dann in der unter Beispiel 1 angegebenen Weise.A component made of an austenitic iron alloy of the type X10CrNiW 17/13 was used as the workpiece. It was first degreased in organic solvents and then installed in a suitable rack. The procedure of Example 1 was also followed. The cell voltage was kept at 70 V during the electrolytic polishing. The polishing time was 7 min. The workpiece was then treated in the manner specified in Example 1.

Die Erfindung ist nicht auf die Ausführungsbeispiel beschränkt. Das Verfahren ist grundsätzlich auf Ni-, Co- oder Fe-Basislegierungen - vorwiegend austenitische Werkstoffe anwendbar. Dem in der Regel auf einer konzentrierten nichtoxydierenden Säure wie H2S04 oder H3P04 aufgebauten, ferner ein Fluorotensid und eine schwache polare organische Verbindung enthaltenden Elektrolyten wird eine Fluorverbindung in Form eines einfachen oder komplexen Fluorids in einer Menge von mindeatens 2 Vol.-% beige mengt.The invention is not restricted to the exemplary embodiment. The process is basically applicable to Ni, Co or Fe-based alloys - mainly austenitic materials. The electrolyte, which is usually built on a concentrated non-oxidizing acid such as H 2 S0 4 or H 3 P0 4 and also contains a fluorosurfactant and a weak polar organic compound, is converted into a fluorine compound in the form of a simple or complex fluoride in an amount of at least 2 vol. -% beige quantity.

Der Gehalt an konzentrierter H2S04 oder H3P04 kann zwischen 20 und 80 Vol.-% betragen. Würden beide vorgenannten Säuren gleichzeitig verwendet, so betrüge deren Gehalt vorteilhafterweise je 10 bis 40 Vol.-%.The content of concentrated H 2 S0 4 or H 3 P0 4 can be between 20 and 80 vol .-%. If both of the aforementioned acids were used at the same time, their content would advantageously be 10 to 40% by volume.

Als schwach polare organische Verbindungen werden vorzugsweise 10 bis 50 Vol.-% C2H5OH und 5 bis 40 Vol.-% Glyzerin verwendet. Statt dessen können im Elektrolyten auch je 10 bis 30 Vol.-% C2H5OH und 2-Propanol enthalten sein. Durchwegs werden dem Elektrolyten ca. 0,2 Vol.- % eines Fluorotensids beigegeben.10 to 50% by volume of C 2 H 5 OH and 5 to 40% by volume of glycerol are preferably used as weakly polar organic compounds. Instead, the electrolyte may also contain 10 to 30% by volume of C 2 H 5 OH and 2-propanol. Approximately 0.2% by volume of a fluorosurfactant is added to the electrolyte throughout.

Als Fluorverbindungen, welche für das Verfahren geeignet und typisch sind, können HBF4 (5 bis 40 Vol.-%); Ammoniumdifluorid (5 bis 40 Vol.-%) oder eine Mischung von HF und Natriumfluorsilikat (je 5 bis 20 Vol.-%) Verwendung finden. Selbstverständlich sind auch andere Kombinationen von geeigneten Fluorverbindungen für die Durchführung des Verfahrens verwendbar.As fluorine compounds which are suitable and typical for the process, HBF 4 (5 to 40% by volume); Ammonium difluoride (5 to 40 vol .-%) or a mixture of HF and sodium fluorosilicate (each 5 to 20 vol .-%) are used. Of course, other combinations of suitable fluorine compounds can also be used to carry out the process.

Das elektrolytische Polieren wird vorteilhafterweise bei Temperaturen zwischen -20 und +30 ° C bei anodischen Stromdichten von 20 bis 250 A/dm2 unter Zellenspannungen von 20 bis 70 V während 20 sec bis 20 min durchgeführt.The electrolytic polishing is advantageously carried out at temperatures between -20 and +30 ° C at anodic current densities of 20 to 250 A / dm 2 under cell voltages of 20 to 70 V for 20 sec to 20 min.

Claims (6)

1. Process for electrolytic polishing of a workpiece consisting of an alloy based on nickel, cobalt or iron by means of an electrolyte containing a concentrated nonoxidizing acid as well as a fluorosurfactant and a weekly polar organic compound, the workpiece being first degreased and, after polishing, being rinsed and dried, characterized in that at least one fluorine compound in the form of a simple or complex fluoride is admixed in a quantity of at least 2% by volume to the electrolyte, and that polishing is carried out in the temperature range from -20 to +30° Cat a current density of 20 to 250 A/dm2 under a voltage of 20 to 70 V for a period of 20 seconds to 20 minutes.
2. Process according to Claim 1, characterized in that the electrolyte contains 20 to 80% by volume of concentrated H2S04.
3. Process according to Claim 2, characterized in that the electrolyte contains 20 to 60% by volume of concentrated H2S04, 10 to 50% by volume of C2H50H, 5 to 40% by volume of glycerol, 5 to 40% by volume of HBF4 and 0.1% by volume of a fluorosurfactant.
4. Process according to Claim 1, characterized in that the electrolyte contains 20 to 60% by volume of concentrated H3P04.
5. Process according to Claim 4, characterized in that the electrolyte contains 20 to 60% by volume of concentrated H3P04, 10 to 50% by volume of C2H50H, 5 to 40% by volume of glycerol, 5 to 40% by volume of ammonium difluoride and 0.1% by volume of a fluorosurfactant.
6. Process according to Claim 1, characterized in that the electrolyte contains 10 to 40% by volume each of concentrated H2SO4 and H3PO4 and also 10 to 30% by volume each of C2H50H and 2-propanol, 5 to 20% by volume each of HF and sodium fluosilicate and 0.1% by volume of a fluorosurfactant.
EP84109758A 1983-08-23 1984-08-16 Process for electrolytically polishing a work piece made of a nickel, cobalt or iron based alloy Expired EP0139958B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH4580/83 1983-08-23
CH458083 1983-08-23

Publications (2)

Publication Number Publication Date
EP0139958A1 EP0139958A1 (en) 1985-05-08
EP0139958B1 true EP0139958B1 (en) 1986-11-05

Family

ID=4278751

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84109758A Expired EP0139958B1 (en) 1983-08-23 1984-08-16 Process for electrolytically polishing a work piece made of a nickel, cobalt or iron based alloy

Country Status (4)

Country Link
US (1) US4563257A (en)
EP (1) EP0139958B1 (en)
JP (1) JPS60100700A (en)
DE (1) DE3461202D1 (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5574486A (en) * 1993-01-13 1996-11-12 Tektronix, Inc. Ink jet print heads and methos for preparing them
US6409936B1 (en) 1999-02-16 2002-06-25 Micron Technology, Inc. Composition and method of formation and use therefor in chemical-mechanical polishing
US6426295B1 (en) * 1999-02-16 2002-07-30 Micron Technology, Inc. Reduction of surface roughness during chemical mechanical planarization(CMP)
DE10320909A1 (en) * 2003-05-09 2004-11-18 Poligrat Holding Gmbh Electrolyte for the electrochemical polishing of metal surfaces
WO2005005693A1 (en) * 2003-07-01 2005-01-20 Superpower, Inc. Process control methods of electropolishing for metal substrate preparation in producing ybco coated conductors
PL2504469T3 (en) * 2009-11-23 2018-12-31 Metcon, Llc Electropolishing methods
US8580103B2 (en) 2010-11-22 2013-11-12 Metcon, Llc Electrolyte solution and electrochemical surface modification methods
GB201200360D0 (en) * 2012-01-11 2012-02-22 Rolls Royce Plc Component production method
US9162301B2 (en) * 2012-08-06 2015-10-20 General Electric Company Electrochemical machining tools and methods
US9163322B2 (en) * 2013-07-01 2015-10-20 General Electric Company Method and apparatus for refurbishing turbine components
CN115353808B (en) * 2022-07-13 2024-01-23 锦矽半导体(上海)有限公司 Polishing solution for nickel plating

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2542779A (en) * 1948-01-07 1951-02-20 Columbus Metal Products Inc Electropolishing composition and process
GB837703A (en) * 1955-08-04 1960-06-15 Minnesota Mining & Mfg Improvements in or relating to methods for reducing the surface tension of liquids
DE1220697B (en) * 1962-08-07 1966-07-07 Manfred Ohle Self-regulating bath for anodic polishing of metals
BE655689A (en) * 1963-11-14 1965-03-01
US3239440A (en) * 1964-11-23 1966-03-08 Titanium Metals Corp Electrolytic pickling of titanium and titanium base alloy articles
US3389065A (en) * 1964-12-28 1968-06-18 Kyowa Hakko Kogyo Kk Method for electrolytically polishing stainless steel
US3627654A (en) * 1969-11-19 1971-12-14 Atomic Energy Commission Electrolytic process for cleaning high-carbon steels
HU178066B (en) * 1978-03-22 1982-02-28 Latszereszeti Eszkoezek Gyara Process and circuit arrangement for optimum control of electrolytic polishing

Also Published As

Publication number Publication date
JPS60100700A (en) 1985-06-04
DE3461202D1 (en) 1986-12-11
EP0139958A1 (en) 1985-05-08
US4563257A (en) 1986-01-07

Similar Documents

Publication Publication Date Title
DE2907875C2 (en) Process for the electrolytic removal of tungsten carbide coatings on workpieces made of titanium or titanium alloys
EP0139958B1 (en) Process for electrolytically polishing a work piece made of a nickel, cobalt or iron based alloy
EP0249650B1 (en) Electrolyte for electrochemically polishing metal surfaces
DE102006047713B3 (en) Electrolyte for electro-polishing surfaces of metal and metal alloys used in the production of gas turbines contains methane sulfonic acid and ammonium difluoride
DE1094245B (en) Lead dioxide electrode for use in electrochemical processes
DE3020012C2 (en) Method of exposing the silicon crystals on the surface of a body made of an aluminum alloy with a high silicon content
DE3706711A1 (en) METHOD FOR CLEANING SURFACES OF AN ALUMINUM OBJECT
DE3125565A1 (en) "ELECTROCHEMICAL DE-METALIZING BATH AND METHOD FOR DE-METALIZING"
DE2201015C2 (en) Process for the manufacture of a lead dioxide electrode
DE2949807B1 (en) Electrolyte solution for electropolishing
DE2654484A1 (en) ELECTROLYTE FOR THE ELECTROCHEMICAL PROCESSING OF NICKEL-BASED SUPER ALLOYS
DE3033961C2 (en) Aqueous bath for anodically removing metal coatings from a different base metal and a method for anodically removing metal coatings using this bath
DE19931820C2 (en) Process for descaling titanium material and descaled titanium material
DE3307834A1 (en) METHOD FOR THE ELECTROLYTIC REMOVAL OF COATS FROM NICKEL OR NICKEL-IRON ALLOYS OF BASE METALS FROM COPPER OR COPPER ALLOYS
DE1521464A1 (en) Process for applying adhesive deposits of metals of the platinum group to objects made of titanium
US3829367A (en) Electrolytic polishing of metals
DE743258C (en) Electrolytic process for the production of a copper layer on the surface of workpieces made of brass and brass-like alloys from copper-free solutions
DE2310638A1 (en) PROCESS FOR CONVERTING HYDROPHOBIC SURFACES MADE OF ALUMINUM, ALUMINUM ALLOYS, COPPER OR COPPER ALLOYS INTO HYDROPHILIC SURFACES
DE1546077C3 (en) Process for the electrolytic removal of oxides from the surface of stainless steel
DE3142488C2 (en)
DE2306957C3 (en) Process for the production of electrodes for electrolytic purposes, in particular for lead accumulators
AT272039B (en) Process for anodic electrolytic descaling of materials made of iron and steel
DE2150080A1 (en) Process for controlling the chlorine concentration in immersion copper coating solutions
DE942428C (en) Process for galvanic chrome plating of objects
DE821898C (en) Process for anodic treatment of objects made of aluminum or aluminum alloys

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): CH DE FR GB LI

17P Request for examination filed

Effective date: 19850621

17Q First examination report despatched

Effective date: 19860326

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): CH DE FR GB LI

REF Corresponds to:

Ref document number: 3461202

Country of ref document: DE

Date of ref document: 19861211

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19890816

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19890831

Ref country code: CH

Effective date: 19890831

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19900427

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19900501

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST