EP0263469B1 - Method for thermally coating surfaces - Google Patents

Method for thermally coating surfaces Download PDF

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Publication number
EP0263469B1
EP0263469B1 EP87114518A EP87114518A EP0263469B1 EP 0263469 B1 EP0263469 B1 EP 0263469B1 EP 87114518 A EP87114518 A EP 87114518A EP 87114518 A EP87114518 A EP 87114518A EP 0263469 B1 EP0263469 B1 EP 0263469B1
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EP
European Patent Office
Prior art keywords
carbon dioxide
medium
admixed
nozzle
cooling
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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
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EP87114518A
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German (de)
French (fr)
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EP0263469A1 (en
Inventor
Helmut Dipl.-Ing. Meinass
Peter Dipl.-Ing. Heinrich (Fh)
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Linde GmbH
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Linde GmbH
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Priority to AT87114518T priority Critical patent/ATE43256T1/en
Publication of EP0263469A1 publication Critical patent/EP0263469A1/en
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Publication of EP0263469B1 publication Critical patent/EP0263469B1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/02—Processes for applying liquids or other fluent materials performed by spraying
    • B05D1/08—Flame spraying
    • 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
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
    • C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
    • C23C4/129—Flame spraying
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/04—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases
    • B05D3/0466—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases the gas being a non-reacting gas
    • B05D3/048—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases the gas being a non-reacting gas for cooling

Definitions

  • the invention relates to a method for the thermal coating of surfaces of workpieces with a jet of a heated gas and a liquefied material with simultaneous cooling of the surfaces with a cooling jet containing carbon dioxide and generated in a nozzle, the carbon dioxide being supplied to the nozzle opening in liquid form.
  • Methods of this type are used to coat workpieces on their surface with a layer of a selected material, in order to refine them in a certain way which is adapted to the intended use.
  • workpieces consist, for example, of metal, ceramic or glass, which e.g. be coated with layers of high-melting metals or with ceramic layers.
  • plasma spraying method is predominantly used in recent times, in which a gas is heated and ionized and the material to be liquefied is introduced in powder form into the ionized gas jet.
  • the workpiece to be coated is cooled with carbon dioxide in the immediate vicinity of the point of impact of the coating jet.
  • carbon dioxide is fed liquid to a nozzle, from which it then emerges as a mixture of gaseous and solid carbon dioxide (DE-C 26 15 022).
  • the invention is therefore based on the object of improving the method for thermal coating of surfaces described at the outset by targeted further development of workpiece cooling with carbon dioxide.
  • This object is achieved in that a further medium with a smaller molar mass than carbon dioxide is added to the carbon dioxide before or when it emerges from the nozzle opening.
  • the inventive admixture of a further gaseous or liquid medium of smaller molar mass to the carbon dioxide as a coolant increases the cooling effect of the cooling medium considerably, since the thermal conductivity of the cooling medium mixture thus obtained is greater than that of carbon dioxide.
  • the applied coatings adhere particularly well to the workpieces and cracking is virtually impossible. This applies especially to previously difficult to coat high temperature sensitive workpieces, e.g. brittle ceramics or glass materials.
  • the spraying of coatings onto small workpieces or those with multi-axis clamping states is also considerably safer with the method according to the invention and thus leads to products of consistently high quality. It is also essential that the cooling medium also acts as a protective gas for the initially hot and therefore easily oxidizable coating.
  • the process according to the invention is particularly advantageous if hydrogen or helium or a hydrogen-helium mixture in the gaseous state is used as the medium to be mixed, since these gases have a thermal conductivity that is more than a decade higher than that of carbon dioxide.
  • the amount of the medium to be mixed with the carbon dioxide is between 5 and 30% by volume, preferably between 10 and 20% by volume, in each case of the total amount of the cooling medium.
  • the admixing of the additional media to the carbon dioxide is expediently carried out under pressure in a nozzle system with mixing nozzles, to which the carbon dioxide is supplied in liquid form and the additional medium in gaseous or liquid form.
  • a variant is particularly expedient in which the carbon dioxide and the medium to be mixed emerge separately from a nozzle system and meet and mix directly in the area of the outlet.
  • thermal conductivity of two mixtures according to the invention are compared with that of carbon dioxide in the following table.
  • the thermal conductivity compared to carbon dioxide is increased to about twice with mixture 1 and almost three times with mixture 2.
  • a significant reduction in gas costs is also achieved, since cooling gas can be saved overall.
  • the workpiece 1 shows a cylindrical workpiece 1, the surface of which is to be coated with a high-temperature-resistant metal.
  • the workpiece 1 is rotated about its longitudinal axis 2 in the direction of the arrow and exposed to a beam 3 which ionized gas, e.g. Contains argon and liquefied metal.
  • ionized gas e.g. Contains argon and liquefied metal.
  • the ionized gas is heated in a plasma torch 4, while the metal is introduced in powder form into the hot gas jet 3 via a powder feed 5.
  • the rotating workpiece 1 is cooled by a gas jet 6, which emerges from a mixing nozzle 7, e.g. in the manner of the nozzles shown in Figures 2 and 3, emerges.
  • the cooling gas consists, for example, of a mixture of 80 vol% carbon dioxide and 20 vol% helium. This process also allows workpieces 1 of the smallest dimensions to be coated safely and economically.
  • FIGS. 2a and 2b show two so-called internally mixing nozzles which are particularly suitable for generating the cooling gas jet 6.
  • carbon dioxide in liquid form is added to the channels 7 and, according to the invention, the additional medium, e.g. gaseous helium, each fed under pressure.
  • the mixing of the two media takes place in the nozzle according to FIG. 2a, shortly before the nozzle outlet and the associated expansion of the gas mixture, in the nozzle according to FIG Feed pipe 9.
  • liquid carbon dioxide is fed through the central bore 10 to the nozzle 11, where gaseous and solid carbon dioxide is produced by the expansion.
  • the additional medium is fed under pressure through the cross sections 12 to special nozzles 13 and is expanded there.
  • the nozzles 13 are arranged so that the media mix immediately after exiting the nozzles 11 and 13.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Nozzles (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)

Abstract

1. A process for the thermal coating of surfaces of work-pieces (1) with a jet (3) comprising a heated gas and a liquefied material whilst simultaneously cooling the surfaces with a cooling jet (6) which contains carbon dioxide and is produced in a nozzle (7), the carbon dioxide being supplied to the nozzle opening in liquid form, characterized in that a further medium having a lower molecular weight than carbon dioxide is admixed with the carbon dioxide prior to or at the time of its exit from the nozzle opening.

Description

Die Erfindung betrifft ein Verfahren zum thermischen Beschichten von Oberflächen von Werkstücken mit einem Strahl aus einem erhitzten Gas und einem verflüssigten Werkstoff unter gleichzeitiger Kühlung der Oberflächen mit einem Kohlendioxid enthaltenden und in einer Düse erzeugten Kühlstrahl, wobei das Kohlendioxid der Düsenöffnung in flüssiger Form zugeführt wird.The invention relates to a method for the thermal coating of surfaces of workpieces with a jet of a heated gas and a liquefied material with simultaneous cooling of the surfaces with a cooling jet containing carbon dioxide and generated in a nozzle, the carbon dioxide being supplied to the nozzle opening in liquid form.

Verfahren dieser Art werden dazu benutzt, Werkstücke an ihrer Oberfläche mit einer Schicht eines ausgewählten Werkstoffes zu beschichten, um sie damit in einer bestimmten, dem Verwendungszweck angepaßten Weise zu veredeln. Solche Werkstücke bestehen beispielsweise aus Metall, Keramik oder Glas, die z.B. mit Schichten hochschmelzender Metalle oder auch mit keramischen Schichten überzogen werden. Zur Herstellung dieser Beschichtungen wird in neuerer Zeit überwiegend das sogenannte Plasmaspritzverfahren benutzt, bei dem ein Gas erhitzt und ionisiert wird und der zu verflüssigende Werkstoff pulverförmig in den ionisierten Gasstrahl eingetragen wird.Methods of this type are used to coat workpieces on their surface with a layer of a selected material, in order to refine them in a certain way which is adapted to the intended use. Such workpieces consist, for example, of metal, ceramic or glass, which e.g. be coated with layers of high-melting metals or with ceramic layers. For the production of these coatings, the so-called plasma spraying method is predominantly used in recent times, in which a gas is heated and ionized and the material to be liquefied is introduced in powder form into the ionized gas jet.

Bei einem bekannten Verfahren zum Plasmaspritzen wird das zu beschichtende Werkstück in unmittelbarer Umgebung der Auftreffstelle des Beschichtungsstrahles mit Kohlendioxid gekühlt. Um einen ausreichenden Kühleffekt zu erreichen, wird dabei das Kohlendioxid einer Düse flüssig zugeführt, aus der es dann als ein Gemisch aus gasförmigem und festem Kohlendioxid austritt (DE-C 26 15 022).In a known method for plasma spraying, the workpiece to be coated is cooled with carbon dioxide in the immediate vicinity of the point of impact of the coating jet. In order to achieve a sufficient cooling effect, the carbon dioxide is fed liquid to a nozzle, from which it then emerges as a mixture of gaseous and solid carbon dioxide (DE-C 26 15 022).

Die bekannten Verfahren zum thermischen Beschichten von Oberflächen haben sich in der Praxis zwar weitgehend bewährt, doch ergeben sich immer wieder Anwendungsfälle, bei denen die erzeugten Produkte nicht in vollem Umfange den gewünschten Qualitätsanforderungen genügen. Dies gilt insbesondere für hochtemperaturempfindliche Werkstücke, für kleine Gegenstände, sowie für Gegenstände, bei denen mehrachsige Spannungszustände auftreten können. Die Ursache für die Unsulänglichkeit der beschichteten Werkstücke ist im allgemeinen in einer ungenügenden Kühlung und damit in einer Überhitzung der Werkstückoberflächen zu sehen.The known methods for the thermal coating of surfaces have largely proven their worth in practice, but there are always applications in which the products produced do not fully meet the desired quality requirements. This applies in particular to workpieces that are sensitive to high temperatures, to small objects, and to objects in which multi-axis stress conditions can occur. The reason for the inadequacy of the coated workpieces can generally be seen in insufficient cooling and thus in overheating of the workpiece surfaces.

Der Erfindung liegt deshalb die Aufgabe zugrunde, das eingangs beschriebene Verfahren zum thermischen Beschichten von Oberflächen durch eine gezielte Weiterentwicklung der Werkstückskühlung mit Kohlendioxid zu verbessern.The invention is therefore based on the object of improving the method for thermal coating of surfaces described at the outset by targeted further development of workpiece cooling with carbon dioxide.

Diese Aufgabe wird dadurch gelöst, daß dem Kohlendioxid vor oder beim Austritt aus der Düsenöffnung ein weiteres Medium mit einer kleineren Molmasse als Kohlendioxid zugemischt wird.This object is achieved in that a further medium with a smaller molar mass than carbon dioxide is added to the carbon dioxide before or when it emerges from the nozzle opening.

Durch die erfindungsgemäße Zumischung eines weiteren gasförmigen oder flüssigen Mediums kleinerer Molmasse zum Kohlendioxid als Kühlmittel wird die Kühlwirkung des Kühlmediums erheblich gesteigert, da die Wärmeleitfähigkeit des so erhaltenen Kühlmedien-Gemisches größer ist als diejenige von Kohlendioxid. Überraschenderweise hat sich gezeigt, daß aufgrund dieser Steigerung der Wärmeleitfähigkeit des Kühlmediums und damit einer Verminderung der Erhitzung der Werkstückoberflächen die aufgebrachten Beschichtungen besonders gut an den Werkstücken haften und eine Rißbildung so gut wie ausgeschlossen ist. Dies gilt vor allem für bisher schwierig zu beschichtende hochtemperaturempfindliche Werkstücke, z.B. spröde Keramik oder Glasmaterialien. Auch das Aufspritzen von Überzügen auf kleine Werkstücke oder solche mit mehrachsigen Spannungszuständen wird mit dem erfindungsgemäßen Verfahren wesentlich sicherer und führt damit zu Produkten gleichbleibender hoher Qualität. Von wesentlicher Bedeutung ist hierbei außerdem, daß das Kühlmedium auch als Schutzgas für die zunächst noch heiße und deshalb leicht oxidierbare Beschichtung wirkt.The inventive admixture of a further gaseous or liquid medium of smaller molar mass to the carbon dioxide as a coolant increases the cooling effect of the cooling medium considerably, since the thermal conductivity of the cooling medium mixture thus obtained is greater than that of carbon dioxide. Surprisingly, it has been shown that due to this increase in the thermal conductivity of the cooling medium and thus a reduction in the heating of the workpiece surfaces, the applied coatings adhere particularly well to the workpieces and cracking is virtually impossible. This applies especially to previously difficult to coat high temperature sensitive workpieces, e.g. brittle ceramics or glass materials. The spraying of coatings onto small workpieces or those with multi-axis clamping states is also considerably safer with the method according to the invention and thus leads to products of consistently high quality. It is also essential that the cooling medium also acts as a protective gas for the initially hot and therefore easily oxidizable coating.

Besonders vorteilhaft ist das erfindungsgemäße Verfahren, wenn als zuzumischendes Medium Wasserstoff oder Helium oder ein Wasserstoff-Helium-Gemisch in gasförmigem Zustand verwendet wird, da diese Gase gegenüber Kohlendioxid eine um mehr als eine Zehnerpotenz höhere Wärmeleitfähigkeit aufweisen.The process according to the invention is particularly advantageous if hydrogen or helium or a hydrogen-helium mixture in the gaseous state is used as the medium to be mixed, since these gases have a thermal conductivity that is more than a decade higher than that of carbon dioxide.

Es hat sich gezeigt, daß die besten Ergebnisse erzielt werden, wenn die Menge des dem Kohlendioxid zuzumischenden Mediums zwischen 5 und 30 vol-%, vorzugsweise zwischen 10 und 20 vol-%, jeweils der gesamten Menge des Kühlmediums liegt. Bei der Zumischung brennbarer Medien, z.B. von Wasserstoff, ist selbstverständlich zu beachten, daß die Mischungen unterhalb den Explosionsgrenzen bleiben. Die Zumischung der Zusatzmedien zum Kohlendioxid erfolgt zweckmäßigerweise unter Druck in einem Düsensystem mit Mischdüsen, dem das Kohlendioxid flüssig und das Zusatzmedium gasförmig oder flüssig zugeführt werden. Für bestimmte Anwendungsfälle besonders zweckmäßig ist hierbei eine Variante, bei der das Kohlendioxid und das zuzumischende Medium getrennt aus einem Düsensystem austreten und unmittelbar im Bereich des Austritts aufeinandertreffen und vermischt werden.It has been shown that the best results are achieved if the amount of the medium to be mixed with the carbon dioxide is between 5 and 30% by volume, preferably between 10 and 20% by volume, in each case of the total amount of the cooling medium. When adding flammable media, e.g. of hydrogen, it should of course be noted that the mixtures remain below the explosion limits. The admixing of the additional media to the carbon dioxide is expediently carried out under pressure in a nozzle system with mixing nozzles, to which the carbon dioxide is supplied in liquid form and the additional medium in gaseous or liquid form. For certain applications, a variant is particularly expedient in which the carbon dioxide and the medium to be mixed emerge separately from a nozzle system and meet and mix directly in the area of the outlet.

Zur Verdeutlichung der Steigerung der Wärmeleitfähigkeit des Kühlmediums durch die erfindungsgemäße Zumischung eines Zusatzmediums geringerer Molmasse als Kohlendioxid, werden in der folgenden Tabelle die Wärmeleitfähigkeiten zweier erfindungsgemäßer Mischungen mit derjenigen von Kohlendioxid verglichen.

Figure imgb0001
In order to clarify the increase in the thermal conductivity of the cooling medium by adding an additional medium of lower molecular weight than carbon dioxide according to the invention, the thermal conductivity of two mixtures according to the invention are compared with that of carbon dioxide in the following table.
Figure imgb0001

Wie aus der Tabelle zu entnehmen ist, wird die Wärmeleitfähigkeit gegenüber Kohlendioxid beim Gemisch 1 auf etwa das Doppelte und beim Gemisch 2 auf nahezu das Dreifache erhöht. Mit solchen Gemischen wird neben der Steigerung der Qualität der Produkte auch eine erhebliche Verminderung der Gaskosten erziehlt, da insgesamt Kühlgas eingespart werden kann.As can be seen from the table, the thermal conductivity compared to carbon dioxide is increased to about twice with mixture 1 and almost three times with mixture 2. With such mixtures, in addition to increasing the quality of the products, a significant reduction in gas costs is also achieved, since cooling gas can be saved overall.

Weitere Einzelheiten der Erfindung werden anhand der in den Figuren schematisch dargestellten Ausführugsbeispiele beschrieben.Further details of the invention are described with reference to the exemplary embodiments shown schematically in the figures.

Hierbei zeigt:

  • Figur 1 eine schematische Darstellung eines Anwendungsfalles des Plasmaspritzverfahrens mit erfindungsgemäßer Kühlung
  • Figuren 2a und 2b Innenmischende Düsen zur Durchführung des erfindungsgemäßen Verfahrens
  • Figur 3 eine außenmischende Düse zur Durchführung des erfindungsgemäßen Verfahrens.
Here shows:
  • Figure 1 is a schematic representation of an application of the plasma spraying method with cooling according to the invention
  • Figures 2a and 2b internally mixing nozzles for performing the method according to the invention
  • Figure 3 shows an external mixing nozzle for performing the method according to the invention.

In Figur 1 ist ein zylindrisches Werkstück 1 dargestellt, dessen Oberfläche mit einem hochtemperaturbeständigen Metall beschichtet werden soll. Zu diesem Zweck wird das Werkstück 1 um seine Längsachse 2 in Pfeilrichtung gedreht und einem Strahl 3 ausgesetzt, der ionisiertes Gas, z.B. Argon, und verflüssigtes Mertall enthält. Das ionisierte Gas wird in einem Plasmabrenner 4 erhitzt, während das Metall pulverförmig über eine Pulverzuführung 5 in den heißen Gasstrahl 3 eingebracht wird.1 shows a cylindrical workpiece 1, the surface of which is to be coated with a high-temperature-resistant metal. For this purpose, the workpiece 1 is rotated about its longitudinal axis 2 in the direction of the arrow and exposed to a beam 3 which ionized gas, e.g. Contains argon and liquefied metal. The ionized gas is heated in a plasma torch 4, while the metal is introduced in powder form into the hot gas jet 3 via a powder feed 5.

Das sich drehende Werkstück 1 wird erfindungsgemäß durch einen Gasstrahl 6 gekühlt, der aus einer Mischdüse 7, z.B. in der Art der in den Figuren 2 und 3 dargestellten Düsen, austritt. Das Kühlgas besteht beispielsweise aus einem Gemisch von 80 vol-% Kohlendioxid und 20 vol-% Helium. Dieses Verfahren erlaubt es auch, Werkstücke 1 kleinster Abmessungen sicher und wirtschaftlich zu beschichten.According to the invention, the rotating workpiece 1 is cooled by a gas jet 6, which emerges from a mixing nozzle 7, e.g. in the manner of the nozzles shown in Figures 2 and 3, emerges. The cooling gas consists, for example, of a mixture of 80 vol% carbon dioxide and 20 vol% helium. This process also allows workpieces 1 of the smallest dimensions to be coated safely and economically.

In den Figuren 2a und 2b sind zwei sogenannte innenmischende Düsen dargestellt, die besonders geeignet sind, den Kühlgasstrahl 6 zu erzeugen. Bei diesen Düsen wird in die Kanäle 7 Kohlendioxid in flüssiger Form und in die Kanäle 8 erfindungsgemäß das Zusatzmedium, z.B. gasförmiges Helium, jeweils unter Druck eingespeist. Die Mischung der beiden Medien erfolgt bei der Düse gemäß Figur 2a, kurz vor dem Düsenaustritt und der damit verbundenen Entspannung des Gasgemisches, bei der Düse gemäß Figur 2b bei der das Zuführungsrohr 9 teilweise aus gasdurchlässigem Material besteht, im Bereich des Gasaustritts aus den Poren des Zuführungsrohres 9.FIGS. 2a and 2b show two so-called internally mixing nozzles which are particularly suitable for generating the cooling gas jet 6. In these nozzles, carbon dioxide in liquid form is added to the channels 7 and, according to the invention, the additional medium, e.g. gaseous helium, each fed under pressure. The mixing of the two media takes place in the nozzle according to FIG. 2a, shortly before the nozzle outlet and the associated expansion of the gas mixture, in the nozzle according to FIG Feed pipe 9.

Bei der in Figur 3 dargestellten außenmischenden Düse wird flüssiges Kohlendioxid durch die mittlere Bohrung 10 zu der Düse 11 geführt, wo durch die Entspannung gasförmiges und festes Kohlendioxid entsteht. Das Zusatzmedium wird unter Druck durch die Querschnitte 12 speziellen Düsen 13 zugeleitet und dort entspannt. Die Düsen 13 sind so angeordnet, daß sich die Medien unmittelbar nach dem Austritt aus den Düsen 11 und 13 mischen.In the case of the external mixing nozzle shown in FIG. 3, liquid carbon dioxide is fed through the central bore 10 to the nozzle 11, where gaseous and solid carbon dioxide is produced by the expansion. The additional medium is fed under pressure through the cross sections 12 to special nozzles 13 and is expanded there. The nozzles 13 are arranged so that the media mix immediately after exiting the nozzles 11 and 13.

Claims (4)

1. A process for the thermal coating of surfaces of work-pieces (1) with a jet (3) comprising a heated gas and a liquefied material whilst simultaneously cooling the surfaces with a cooling jet (6) which contains carbon dioxide and is produced in a nozzle (7), the carbon dioxide being supplied to the nozzle opening in liquid form, characterised in that a further medium having a lower molecular weight than carbon dioxide is admixed with the carbon dioxide prior to or at the time of its exit from the nozzle opening.
2. A process as claimed in Claim 1, characterised in that hydrogen, or helium, or a hydrogen-helium mixture in a gaseous state is used as the medium to be admixed.
3. A process as claimed in Claim 1 or 2, characterised in that the medium to be admixed is admixed in an amount of 5 to 30 vol.-%, preferably 10 to 20 vol.-%, of the total quantity of cooling medium.
4. A process as claimed in one of Claims 1 to 3, characterised in that the carbon dioxide and the medium to be admixed emerge separately from a nozzle system and meet and are mixed directly in the region of the outlet.
EP87114518A 1986-10-07 1987-10-05 Method for thermally coating surfaces Expired EP0263469B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT87114518T ATE43256T1 (en) 1986-10-07 1987-10-05 PROCESSES FOR THERMAL COATING OF SURFACES.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19863634153 DE3634153A1 (en) 1986-10-07 1986-10-07 METHOD FOR THERMALLY COATING SURFACES
DE3634153 1986-10-07

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EP0263469A1 EP0263469A1 (en) 1988-04-13
EP0263469B1 true EP0263469B1 (en) 1989-05-24

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Publication number Priority date Publication date Assignee Title
DE68908057T2 (en) * 1988-09-14 1993-11-18 Hitachi Chemical Co Ltd Process for producing a metallic strip coated with flame-sprayed ceramic.
DE3844290C1 (en) * 1988-12-30 1989-12-21 Uranit Gmbh, 5170 Juelich, De
DE4031489A1 (en) * 1990-10-05 1992-04-09 Ver Glaswerke Gmbh METHOD FOR COATING GLASS DISCS BY A THERMAL SPRAYING METHOD
DE4204896C2 (en) * 1992-02-19 1995-07-06 Tridelta Gmbh Process for producing a layered composite body
GB9303655D0 (en) * 1993-02-23 1993-04-07 Star Refrigeration Production of heat transfer element
DE4339345C2 (en) * 1993-11-18 1995-08-24 Difk Deutsches Inst Fuer Feuer Process for applying a hard material layer by means of plasma spraying
DE19611735A1 (en) * 1996-03-25 1997-10-02 Air Liquide Gmbh Thermal treatment of substrates
FR2808808A1 (en) * 2000-05-10 2001-11-16 Air Liquide Thermal spraying of titanium on a medical prosthesis involves cooling at least part of the prosthesis with carbon dioxide or argon during the coating process
EP2574408B1 (en) * 2011-09-30 2018-04-11 Air Liquide Deutschland GmbH Method and device for supplying a coolant media flow
CN110513044A (en) * 2019-09-18 2019-11-29 河南理工大学 A kind of forming method and device of self-oscillation supercritical carbon dioxide jet stream

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DE2615022C2 (en) * 1976-04-07 1978-03-02 Agefko Kohlensaeure-Industrie Gmbh, 4000 Duesseldorf Method of coating a surface by means of a jet of heated gas and molten material
DE3217839A1 (en) * 1982-05-12 1983-11-17 Hans Dr.Rer.Nat. 5370 Kall Beerwald PLASMA PROCESS FOR PRODUCING A DIELECTRIC ROD

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ATE43256T1 (en) 1989-06-15
DE3760168D1 (en) 1989-06-29
EP0263469A1 (en) 1988-04-13
DE3634153A1 (en) 1988-04-21

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