EP0237153A1 - Verfahren zum Entfernen von Schutz- und Verbindungsschichten von Metallgegenständen - Google Patents

Verfahren zum Entfernen von Schutz- und Verbindungsschichten von Metallgegenständen Download PDF

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Publication number
EP0237153A1
EP0237153A1 EP87300550A EP87300550A EP0237153A1 EP 0237153 A1 EP0237153 A1 EP 0237153A1 EP 87300550 A EP87300550 A EP 87300550A EP 87300550 A EP87300550 A EP 87300550A EP 0237153 A1 EP0237153 A1 EP 0237153A1
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Prior art keywords
base metal
atmosphere
coating
process according
subjecting
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EP87300550A
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English (en)
French (fr)
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EP0237153B1 (de
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Jack W. Chasteen
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University of Dayton
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University of Dayton
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F1/00—Etching metallic material by chemical means
    • C23F1/10—Etching compositions
    • C23F1/12—Gaseous compositions
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F1/00—Etching metallic material by chemical means
    • C23F1/44—Compositions for etching metallic material from a metallic material substrate of different composition
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G5/00—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents

Definitions

  • the present invention re-lates to a process for removing protective coatings and/or bonding layers from a base metal, and more particularly, to a process:for removing gamma prime bonding layers, intermetallic protective coatings, metallic coatings, and ceramic or oxide-type coatings from a part such as a gas turbine engine component part.
  • Protective coatings and bonding layers are widely used in modern gas turbine engines. The use of such protective coatings and bonding layers permits a designer to specify structural materials of high strength without having to be particularly concerned with the surface stability of the materials. Intermetallic coatings, metalic coatings, and oxide-type coatings in particular are used on metal parts which encounter severe operating conditions at elevated temperatures. Such parts include gas turbine parts such as, the burner assembly, turbine vanes, and blades. Bonding layers are used to achieve a good bond between a base metal and a protective coating between which an adequate bond might not otherwise be obtained.
  • U.S. Patent No. 3;948,687 discloses an aqueous HF-HN0 3 stripping bath in which Cr0 3 is also present for removing aluminized-cases.
  • the stripping bath operates at 85°F.
  • the aluminized case dissolves in the bath and the base metal is not significantly attacked.
  • U.S. Patent No. 4,176,433 discloses a more detailed process for chemically stripping an aluminide protective coating from the internal and external surfaces of a salvageable vane.
  • the part is grit-blasted and then immersed in an agitated nitric acid solution at 75 to 90°F for four hours.
  • the part is then wet abrasive- blasted and immersed in'an agitated nitric acid solution at 75 to 90°F for four hours.
  • the wet abrasive-blasting and immersion in acid are repeated until the coating is removed.
  • U.S. Patent Nos. 4,188,237; 4,324,594; 4,328,044; and 4,405,379 disclose processes for cleaning crack damaged stainless steel, superalloy, solid solution superalloy, and gamma prime hardened nickel alloy parts which render the parts braze repairable.
  • the preferred cleaning process involves a three-stage procedure to eliminate the passivating oxides from the metallic surface.
  • stage I a cleaning atmosphere of carbon, oxygen, hydrogen, and fluorine between 450-800°C, converts noble oxides on the metallic surface and in the cracks to their fluorides.
  • stage II the atmosphere is maintained to draw Al and Ti from the surface by diffusion.
  • stage III a predominantly hydrogen atmosphere between 750 and 1000°C, converts the crystalline non-volatile fluorides to their conjugate metals.
  • This fluorocarbon cleaning process avoids operation-within the sooting range, i.e., the point at which carbon precipitates from the gas phase at the temperature, pressure, and H/0 ratio of the treating atmosphere. If operated in the sooting range, the cracks, which are rich in nucleation sites, gather soot and cannot be cleaned.
  • the present invention provides a process for removing gamma prime bonding layers, intermetallic coat- _ings, metallic coatings, and ceramic or oxide-type coatings from a base metal such as a solid solution superalloy, a gamma prime hardened nickel base alloy, or a cobalt base or iron base superalloy. Removal is accomplished by subjecting the part to an atmosphere containing carbon, oxygen, hydrogen, and fluorine (C-0-H- F ). When using such a gaseous atmosphere under controlled conditions, as described below, it is possible to adequately remove protective coatings and/or bonding layers from a base metal.
  • a key to this coating removal process is control of the C/H and F/H atomic ratios in the C-O-H-F gaseous atmosphere.
  • the protective coatings and/or bonding layers on a base metal can be adequately removed at temperatures of 500 to 900°C.
  • the H/O ratio also must be greater than 10 4 to generate a very low oxygen potential atmosphere.
  • the H/O ratio of 10 4 c or- responds to approximately 200 ppm H 2 0 present as moisture in the hydrogen gas used as a component of the C-O-H-F atmosphere.
  • the stripping atmosphere is generated by pyrolysis of a fluorocarbon resin.
  • a fluorocarbon resin As disclosed in U.S. Patent No. 4,188,237, polytetrafluoroethylene resin liber- ates its monomer when heated to 350°C or higher, and the i rate of evolution sharply increases between 450° and 500°C.
  • the primary objective of the process is to remove the protective coatings and/or bonding layers from the metallic surface; however, if continued, the process can be used to deplete all surfaces, including the surfaces of any cracks or crevices, of Al and Ti to produce a surface that can be wet by brazing alloys.
  • the protective coatings and/or bonding layers are undermined in the process by converting metallic elements such as Al and Cr in the coatings or-bonding layers to their fluorides, AlF 3 and CrF 3 .
  • the volatile fluorides, AlF 3 sublime from the protective coatings and/or bonding layers thereby rendering the coating or layer readily removable by grit-blasting. If the process is allowed to continue, i.e., if diffusion is allowed to continue after the coating has been undermined, Al and Ti are drawn from all surfaces of the base metal and converted to their fluorides. Volatile fluorides, such as AlF 3 , are allowed to sublime from the metallic surface; the non-volatile fluorides, CrF 3 are, at a later stage, reduced to their conjugte metals.
  • the fluoridizing potential of the stripping process of the present invention results in effective removal of protective coatings and/or bonding layers from metallic surfaces.
  • the process operates within the sooting range, i.e., conditions under which carbon precipitates from the stripping atmosphere.
  • the process of the present invention introduces C0 2 into the system. The C0 2 removes any soot deposited on the parts and in the system.
  • the invention provides a process for removing protective coatings and/or bonding layers from a base metal which comprises:
  • Another, more specific object of the present invention is to provide a process for removing protective coatings and/or bonding layers from a base metal such as a solid solution superalloy, a gamma prime hardened nickel base alloy, and a cobalt base or a iron base superalloy part through the use of a C-O-H-F gaseous atmosphere.
  • a base metal such as a solid solution superalloy, a gamma prime hardened nickel base alloy, and a cobalt base or a iron base superalloy part through the use of a C-O-H-F gaseous atmosphere.
  • Another object of the present invention is to provide a process for removing gamma prime bonding layers, intermetallic protective coatings, metallic protective coatings, and ceramic protective coatings from a base metal and depleting the surfaces of the base metals of Al - and Ti so that the base metals are rendered braze repairable.
  • the present invention is useful in removing protective coatings and/or bonding layers from a base metal.
  • Protective coatings removable by the process of the present invention include intermetallic coatings, metallic coatings, and ceramic or oxide-type coatings.
  • intermetallic coatings include aluminide coatings, chromium coatings, chromium-aluminide coatings, and nickel-aluminide coatings.
  • An example of a metallic coating is a chromium-aluminum coating.
  • An example of a ceramic or oxide-type coating is a zirconium-oxide coating.
  • the present invention is also useful in removing any bonding layer which may be interposed between the protective coating and the base metal.
  • bonding layers removable by this process include gamma prime bonding layers, and metal-chromium-aluminum-yttrium layers.
  • the coatings and bonding layers removed by this process typically contain chromium or aluminum and, in addition, may contain elements such as cobalt, yttrium, and iron. These coatings are highly oxidation-and corrosion-resistant. In general, where present, the chromium content is at least 10% while the aluminum. content is at least 5.0%.
  • the present invention will be discussed with reference to the reaction of chromium or aluminum in the coatings since typically these metals are the most difficult to remove.
  • chromium and aluminum fluorides one concomitantly generates the fluorides of more reactive and more easily removable metals in the coating.
  • the discussion refers to removing chromium and aluminum, it is also applicable to the removal of coatings containing large proportions of zirconium, nickel, cobalt, and iron.
  • the stripping process of the present invention can be used to remove coatings and/or bonding layers from a wide variety of base metals, including but not limited to solid solution superalloys, gamma prime hardened nickel base alloys, and cobalt or iron base superalloys.
  • a partial list of nickel-based, gamma prime hardened alloys includes INCO 713C, Mar M-200, Rene 80, Rene 95, Rene 100, Rene 41, Udimet 500, and Udimet 520. These range from low, i.e., Rene 41, to medium, i.e., INCO 713C, to high, i.e., Rene 100, levels of gamma prime hardening. All levels may be stripped by the process of the present invention. While the present invention is not limited to cleaning any particular metal part, representative parts include variations of a turbine disc, blade, or segments from a nozzle guide vane.
  • a C-O-H-F cleaning atmosphere is established which diffuses into the coating and/or bonding layer, and converts the metals (typically Al and Cr) in the coatings or bonding layers to _ their fluorides.
  • the cleaning atmosphere is most readily produced by pyrolyzing a fluorocarbon resin.
  • a preferred fluorocarbon resin is polytetrafluoroethylene (PTFE).
  • the stripping process is carried out in a sealed reaction chamber. Since the chamber is sealed, it is necessary to place a sufficient quantity of the fluorine source in the chamber to react with the fluo- ridizable materials in the coating or bonding layer, and if the process is used to deplete surfaces of Al and Ti, to react with these elements as well.
  • a tandem chamber arrangement is also useful wherein the fluorine source is placed in one chamber where it is pyrolyzed and from which it is fed to a second chamber in which the stripping takes place
  • the process of the present invention is carried out over a temperature range of about 500 to 1000°C and for a reactive time of about 4 hours.
  • the process can be considered in stages.
  • the reactor is heated to pyrolyze the fluorocarbon source.
  • the rate of pyrolysis of the fluorocarbon is controlled to contain the fluoridizing chemicals until they can react.
  • a slow diffusion rate is accommodated via this control and the load is thereby held in a high fluoridizing potential atmosphere up to 12 hours. If the fluorocarbon is pyrolyzed too rapidly, the fluoridizing constituents will be exhausted from the cleaning atmosphere without reacting with the coating or base metal, and the reactor atmosphere may not contain sufficient fluorine constituents to undermine the coating or bonding layer.
  • the fluorine concentration of the atmosphere can be-calculated based on the preloaded mass of the fluorocarbon resin, the pyrolysis rate of the fluorocarbon, and the pyrolysis time. Upon reaching 510°C, the PTFE pyro- lyzes at a rate of 0.021 g/g remaining/min. Based on the fluorine concentration, H 2 is then added to the atmosphere to achieve a C/H ratio of greater than or equal to 0.17, and a F/H ratio of greater than or equal to 0.33. Using PTFE, the C/F ratio is 0.5. The C/H and F/H ratios may be decreased dramatically as temperatures rise while maintaining sooting conditions in-the atmosphere.
  • the pyrolysis of PTFE ends at 550 to 620°C•
  • the reactor is carried to the second stage of the process where the temperature of the system is increased to about 800°C. At this higher temperature, the diffusion rate of the fluorine into the coating increases.
  • the atmosphere is maintained in the temperature range of 700 to 1000°C for a period of time sufficient to undermine the protective coatings or bonding layers.
  • These protective coatings are about 1 to 5 mils in thickness and require about 4 hours to undermine.
  • the atmosphere may be maintained to react with the aluminum and titanium on the metallic surfaces of the base metal for conversion to their fluorides, AlF 3 and TiF x , in accordance with stage II of the cleaning process described in U.S. Patent No. 4,405,379. These reactions deplete the metallic surfaces of Al and Ti, and prevent the oxides of these elements from re-forming upon exposure to air.
  • CrF 3 chromium fluoride
  • the amount of C0 2 that is required to purge the soot is determined by first assuming that all fluorocarbon has formed soot and then assuming thermodynamic equilibrium in the C-CO-C0 2 system. When all of the soot has been oxidized and driven off in the form of CO, the final stage is entered.
  • the CrF 3 that has unavoidably formed is rendered metallic by reduction to its corresponding elemental form as the invention atmosphere is caused to become rich in hydrogen analogous to stage III of U.S. Patent No. 4,405,379.
  • This reaction is performed at temperatures in excess of 750°C and most typically at temperatures ranging from about 900° to 1,000° C.
  • the undermined coating is removed.
  • a preferred removal process is grit-blasting.
  • phase stability diagram of the Figure reveals atmospheres at which aluminum and chromium are _ converted to their fluorides at 550°C.
  • the pressure is fixed at 1.0 atmosphere and the H/O ratio is set at 10 5 .
  • the phase fields are shown imposed on an abscissa which is the F/H ratio and the ordinate which is the C/H ratio.
  • Al and Cr are representative of the elements found in the protective coatings on gas turbine engine parts. Therefore, a Cr-Al-C-O-H-F system is used to illustrate the invention.
  • curve A represents the sooting line, i.e., the point at which carbon can precipitate from the gas phase at the temperature, pressure, and H/O ratio of the treating atmosphere. Sooting is promoted in the present invention in order to obtain a high fluoridizing potential.
  • Curve B in the Figure is the equilibrium line for a Al 2 O 3 (solid) -AlF 3 (gas) system under the system conditions described above.
  • a metal part may have A1 2 0 3 and similar metal oxides on its surface. In this condition, the part cannot be brazed. Above and to the right of curve B, these oxides are converted to fluorides and removed from the metal surface.
  • Curve C on the phase stability diagram separates the oxide (Cr 2 0 3 ) and its fluoride (CrF 3 ). Cr 2 0 3 is present below and to the left of curve C.
  • the process of the present invention operates within the hashed region indicated in the Figure.
  • the C/H ratio is equal to 0.125 while the F/H ratio is equal to 0.025.
  • comparable phase stability diagrams with the corresponding hashed operational region exist for the full temperature range, i.e., 500 to 1000°C, of the process of the present invention.
  • the Al and the Cr in the protective coatings are converted to their fluorides, AlF 3 and CrF 3 .
  • the Al and Cr on the metallic surface convert to their fluorides.
  • the CrF 3 is reduced to Cr.
  • the C/F ratio in the retort is approximately 0.5; a 1:2 ratio of carbon to fluorine atoms is present in the resin.
  • atmospheres having C/F ratios equal to 0.5 can be derived from difluoroethylene and mixtures of tetrafluoromethane and hydrogen among others.
  • Point Q on the Figure signifies a gas composition that is potentially achievable by the preferred embodiment of PTFE and H 2 , and represents an atmosphere which is consonant with the stripping process and reasonable speed.
  • Point Q represents the C and F levels about as low as a practitioner may go to efficiently remove protective coatings and/or bonding layers from gas turbine engine parts.
  • the invention process is performed at a F/H ratio greater than or equal to 0.33, and a C/H ratio greater than or equal to 0.17.
  • Point P represents the typical - process levels.
  • the metallic parts are braze repairable.
  • a successful braze is manifest when braze material is placed at the source of a crack (say 0.001 inch wide and 1/2 inch long) and, at brazing temperature, not only melts and sticks to the parent material, but also runs into and fills the length of the crack.
  • the parts may also be otherwise bonded by carefully performed welding techniques.
  • the most expedient source of the stripping atmosphere is a fluorocarbon resin such-as polytetrafluoroethylene which releases fluorine-containing species upon thermal decomposition.
  • fluorocarbon resins which release gaseous fluorine species upon thermal decomposition may also be used.
  • Decomposed fluorocarbon resin gases are a convenient source of the stripping atmosphere because they are not only moisture-free, but, as indicated above, they also react with moisture otherwise introduced to create an extremely reducing atmosphere.
  • the invention atmosphere can, for example, be generated by reacting hydrogen with any saturated or unsaturated fluorocarbon such as and including difluoromethane (CH 2 F 2 ), tetrafluoromethane (CF 4 ), tetrafluoroethylene (C 2 F 4 ), and many of the freons.
  • the stripping atmosphere may be generated from a mixture of HF, CH 4 , and H 2 .
  • any fluorocarbon resin which can be pyrolyzed may be used in the process of the present invention.
  • the process of the present invention is typically performed at atmospheric pressure.
  • Increased pressure would undoubtedly cause pyrolysis of the resins to occur at higher temperatures where their chemical effects would be more pronounced.
  • aqueous stripping may be used in conjunction with the process of the present invention. After subjecting a part to the instant process and grit-blasting, the part would be aqueous stripped.
  • Aqueous stripping usually involves immersing a part in agitated nitric acid at 75 to 90°F. Aqueous stripping is undesirable because the procedure is somewhat dangerous and produces large volumes of hazardous waste. Also, the use of aqueous solutions tends to result in inner granular attack of the base metal.
  • HPI turbine blades from the Allison TF-41 engine are cast from Mar M 246 alloy and coated with Alpak. These, when removed from an engine in-a service damaged- condition, were placed in a vertical reaction chamber which contained teflon that had been placed on the bottom. The chamber was closed and, while being heated, hydrogen was introduced to impinge on the teflon, rise across the load, and exit at the top. The chamber was heated to 580°C, and the hydrogen turned off while the chamber continued to heat to 800°C. The system was held at 800°C for 1 hour to allow the stripping gases to undermine the coat-- ings. Carbon dioxide was then introduced to purge the soot while the chamber was heated to 950°C where hydrogen was again introduced to reduce the non-volatile fluorides to their conjugate metals.
  • the parts were grit-blasted to remove the undermined coating.
  • the parts were then immersed in a nitric acid solution for 5 to 15 minutes in order to remove the chromium particles entrapped in the cleaned but porous base metal surface. After rinsing and drying, the parts were vacuum brightened at 1100°C for 1/2 hour. The stripped and cleaned-blades were readily brazed or welded.
  • Pieces of Nimonic Alloy 75 from a flame tube of a Rolls Royce Nene engine of the Canadian Air Force T-33 Trainer have one side partially coated with a mixture of Nichrome and Chromium carbide.
  • the opposite side has a bond coating of Metco 443 (a NiCrAlY) and an overlay coating of yttria stabilized zirconia.
  • the zirconia was removed by grit-blasting to reveal the NiCrAlY bond coating, and the bare base metal of the opposite side was masked by a plasma sprayed coating of silicon carbide.
  • the resulting part was placed in a reaction chamber with teflon and the chamber was sealed.
  • the chamber was heated to 450°C, hydrogen was introduced and caused to flow until the chamber reached 580°C where the hydrogen was turned off while the chamber was heated to 800°C.
  • the system was held at 800°C for 1 hour to allow the stripping gases to undermine the coating.
  • Carbon dioxide was introduced to purge the soot, and the chamber was heated to 950°C where hydrogen was again introduced to reduce the non-volatile fluorides to their conjugate metals.
  • the part was grit-blasted and immersed in stripper solution for 15 minutes.
  • the part was removed, grit-blasted, and vacuum brightened at 1100°C for 1/2 hour.
  • the base metal was readily brazed or welded.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)
EP19870300550 1986-02-06 1987-01-22 Verfahren zum Entfernen von Schutz- und Verbindungsschichten von Metallgegenständen Expired EP0237153B1 (de)

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US82671886A 1986-02-06 1986-02-06
US826718 1986-02-06

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EP0237153A1 true EP0237153A1 (de) 1987-09-16
EP0237153B1 EP0237153B1 (de) 1991-05-02

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0416400A1 (de) * 1989-08-25 1991-03-13 Applied Materials, Inc. Reinigungsverfahren für eine Anlage zur Behandlung von Halbleiterscheiben
US5129958A (en) * 1989-09-22 1992-07-14 Applied Materials, Inc. Cleaning method for semiconductor wafer processing apparatus
US5207836A (en) * 1989-08-25 1993-05-04 Applied Materials, Inc. Cleaning process for removal of deposits from the susceptor of a chemical vapor deposition apparatus
DE4228551A1 (de) * 1992-08-27 1994-03-03 Linde Ag Verfahren zur reinigenden Behandlung von Oberflächen mit einem Niederdruckplasma
EP0814179A1 (de) * 1996-06-17 1997-12-29 General Electric Company Verfahren zum Entfernen einer Diffusionsbeschichtung von einer Legierung auf Nickelbasis
WO2000048751A1 (en) * 1999-02-18 2000-08-24 General Electric Company Carbon-enhanced fluoride ion cleaning
EP1076114A1 (de) * 1999-08-11 2001-02-14 General Electric Company Verfahren zur Entfernung von dichten keramischen Wärmedämmschichten von einer Oberfläche
DE19960353A1 (de) * 1999-12-14 2001-06-21 Dechema Deutsche Gesellschaft Fuer Chemisches Apparatewesen, Chemische Technik Und Biotechnologie Ev Verfahren zur Herstellung einer Diffusionsbarriere zur Lebensdauererhöhung von Hochtemperatur-Schutzschichten
EP1275753A1 (de) * 2001-07-12 2003-01-15 Snecma Moteurs Verfahren zum globalen Reparieren eines Gegenstandes beschichtet mit einer Wärmedämmstruktur
WO2019057555A1 (en) * 2017-09-19 2019-03-28 Bortec Gmbh & Co. Kg METHOD FOR ENHANCED PRETREATMENT OF A SURFACE OF A METALLIC SUBSTRATE

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7146990B1 (en) * 2005-07-26 2006-12-12 Chromalloy Gas Turbine Corporation Process for repairing sulfidation damaged turbine components

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US2571328A (en) * 1947-12-22 1951-10-16 Ohio Rubber Co Method of cleaning metal articles of adherent rubber and the like
FR2198004A1 (de) * 1972-09-05 1974-03-29 Gen Electric
EP0003660A1 (de) * 1978-02-02 1979-08-22 The University Of Dayton Verfahren zur Reinigung der Oberfläche von einem nicht hartlötbaren Metallgegenstand
EP0020935A1 (de) * 1979-06-29 1981-01-07 International Business Machines Corporation Gasätzverfahren und Vorrichtung, in der feste Maskiermaterialien zur Veränderung der Ätzgeschwindigkeit Verwendung finden
EP0034041A1 (de) * 1980-02-06 1981-08-19 The University Of Dayton Verfahren zum Reinigen von Metallteilen
US4405379A (en) * 1980-02-06 1983-09-20 University Of Dayton Method for cleaning metal parts

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US4324594A (en) * 1978-02-02 1982-04-13 University Of Dayton Method for cleaning metal parts

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2571328A (en) * 1947-12-22 1951-10-16 Ohio Rubber Co Method of cleaning metal articles of adherent rubber and the like
FR2198004A1 (de) * 1972-09-05 1974-03-29 Gen Electric
EP0003660A1 (de) * 1978-02-02 1979-08-22 The University Of Dayton Verfahren zur Reinigung der Oberfläche von einem nicht hartlötbaren Metallgegenstand
EP0020935A1 (de) * 1979-06-29 1981-01-07 International Business Machines Corporation Gasätzverfahren und Vorrichtung, in der feste Maskiermaterialien zur Veränderung der Ätzgeschwindigkeit Verwendung finden
EP0034041A1 (de) * 1980-02-06 1981-08-19 The University Of Dayton Verfahren zum Reinigen von Metallteilen
US4405379A (en) * 1980-02-06 1983-09-20 University Of Dayton Method for cleaning metal parts

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0416400A1 (de) * 1989-08-25 1991-03-13 Applied Materials, Inc. Reinigungsverfahren für eine Anlage zur Behandlung von Halbleiterscheiben
US5207836A (en) * 1989-08-25 1993-05-04 Applied Materials, Inc. Cleaning process for removal of deposits from the susceptor of a chemical vapor deposition apparatus
US5129958A (en) * 1989-09-22 1992-07-14 Applied Materials, Inc. Cleaning method for semiconductor wafer processing apparatus
DE4228551A1 (de) * 1992-08-27 1994-03-03 Linde Ag Verfahren zur reinigenden Behandlung von Oberflächen mit einem Niederdruckplasma
DE4228551C2 (de) * 1992-08-27 1996-02-22 Linde Ag Verfahren und Anwendung des Verfahrens zur reinigenden Behandlung von Oberflächen mit einem Niederdruckplasma
EP0814179A1 (de) * 1996-06-17 1997-12-29 General Electric Company Verfahren zum Entfernen einer Diffusionsbeschichtung von einer Legierung auf Nickelbasis
WO2000048751A1 (en) * 1999-02-18 2000-08-24 General Electric Company Carbon-enhanced fluoride ion cleaning
US6416589B1 (en) * 1999-02-18 2002-07-09 General Electric Company Carbon-enhanced fluoride ion cleaning
EP1076114A1 (de) * 1999-08-11 2001-02-14 General Electric Company Verfahren zur Entfernung von dichten keramischen Wärmedämmschichten von einer Oberfläche
DE19960353A1 (de) * 1999-12-14 2001-06-21 Dechema Deutsche Gesellschaft Fuer Chemisches Apparatewesen, Chemische Technik Und Biotechnologie Ev Verfahren zur Herstellung einer Diffusionsbarriere zur Lebensdauererhöhung von Hochtemperatur-Schutzschichten
EP1275753A1 (de) * 2001-07-12 2003-01-15 Snecma Moteurs Verfahren zum globalen Reparieren eines Gegenstandes beschichtet mit einer Wärmedämmstruktur
FR2827308A1 (fr) * 2001-07-12 2003-01-17 Snecma Moteurs Procede de reparation globale d'une piece revetue d'une barriere thermique
WO2003006712A1 (fr) * 2001-07-12 2003-01-23 Snecma Moteurs Procede de repartition globale d'une piece revetue d'une barriere thermique
WO2019057555A1 (en) * 2017-09-19 2019-03-28 Bortec Gmbh & Co. Kg METHOD FOR ENHANCED PRETREATMENT OF A SURFACE OF A METALLIC SUBSTRATE
US11492693B2 (en) 2017-09-19 2022-11-08 Bortec Gmbh Pre-treatment process of a surface of a metallic substrate

Also Published As

Publication number Publication date
AU6783987A (en) 1987-08-13
EP0237153B1 (de) 1991-05-02
DE3769677D1 (de) 1991-06-06
AU586530B2 (en) 1989-07-13

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