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EP0062550A1 - Process for the thermochemical treatments of metals by ion bombardment - Google Patents

Process for the thermochemical treatments of metals by ion bombardment Download PDF

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Publication number
EP0062550A1
EP0062550A1 EP82400407A EP82400407A EP0062550A1 EP 0062550 A1 EP0062550 A1 EP 0062550A1 EP 82400407 A EP82400407 A EP 82400407A EP 82400407 A EP82400407 A EP 82400407A EP 0062550 A1 EP0062550 A1 EP 0062550A1
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EP
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Prior art keywords
plasma
pulses
voltage
heating
duration
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EP82400407A
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German (de)
French (fr)
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EP0062550B1 (en
Inventor
Roger Speri
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Innovatique SA
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Vide et Traitement SA
Innovatique SA
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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
    • 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
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/36—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases using ionised gases, e.g. ionitriding

Definitions

  • the present invention relates to a process for thermochemical treatments of metals such as nitriding, carbonitriding, carburizing, metallic deposits under vacuum, etc. by ion bombardment.
  • the treatment medium can be obtained by passing a stream of ammonia gas over the parts, which, when decomposed, releases active nitrogen atoms.
  • the treatment temperature which is of the order of 570 ° C. is then obtained by placing the parts in an electric oven.
  • the parts to be treated are placed in an enclosure containing a gas (NH 3 , molecular nitrogen, H 2 CH 4 ) at low pressure (0.1 to 10 torr).
  • a gas NH 3 , molecular nitrogen, H 2 CH 4
  • This enclosure is equipped with an anode and a cathode, connected to a high voltage electric current generator (between 300 and 1500 V).
  • the cathode is designed so as to support the parts to be treated which are therefore brought to the cathode.
  • the treatment is obtained by creating, between the cathode and the anode, a luminescent discharge which is maintained at the limit of the arc regime.
  • a plasma is created around the part to be treated, composed of nitrogen ions which in fact constitutes the treatment medium.
  • the treatment temperature is then obtained by the heat dissipation generated by the bombardment of the ions on the part (kinetic energy).
  • thermochemical treatment methods by ion bombardment compared to other conventional methods are well known.
  • Another solution envisaged for obtaining an operation free from the risk of arcing consists in using, instead of direct current, high-voltage current pulses, but the total energy of which is maintained at a predetermined value, of so that it is not possible to reach, in the voltage / current discharge curve, the zone corresponding to the arc speed.
  • the invention proposes to make the 2 parameters of the treatment completely independent, namely the production of the treatment medium, that is to say the plasma, and the heating to the treatment temperature of the parts. .
  • a cold plasma is obtained continuously, that is to say a plasma in which the heat energy dissipated during the dissociation remains at a very low level and cannot affect the temperature characteristics of the treatment in progress, in the case of a thermochemical treatment.
  • the heat treatment method involves an oven with a structure similar to that of a conventional heat or thermochemical treatment oven with a rarefied atmosphere equipped with its own heating and control means and comprising furthermore at least one anode and one cathode supporting the parts to be treated. It consists in generating on the workpieces a cold plasma as defined above by establishing between the anode and the cathode a succession of voltage pulses at relatively high frequency and duration very brief and to heat the parts using the above heating means, so as to bring them then to maintain them at the processing temperature.
  • This method also makes it possible to remove the temperature heterogeneities as a function of the parameters linked to the parts such as the shape, the state, the hollow cathode phenomena during the rise in temperature, the dimensions of different parts, etc.
  • the invention also relates to an installation for thermochemical treatment by ion bombardment applying the method according to the invention.
  • this installation involves an oven having a structure similar to that of a conventional heat or thermochemical treatment oven with a rarefied atmosphere, this oven comprising its own heating means, by convection, by radiation, coherent or not, or by induction, its own regulation means, a generator of process gas and current passages passing through the wall of the furnace and connected to the electrodes (anodes-cathodes) used for the generation of the plasma.
  • the supply of these electrodes can be provided from the three-phase or single-phase industrial reed by means of a generator comprising a controlled rectifier making it possible to obtain a variable DC voltage between 0 and the mains voltage, an inverter making it possible to transform this direct voltage in particular alternating voltage with variable amplitude and duty cycle, then rectified to obtain monopolar pulses at high voltage of the order of 300 to 1500 V and at high frequency of the order of 100 Hz to 10 K Hertz which supply the oven.
  • a generator comprising a controlled rectifier making it possible to obtain a variable DC voltage between 0 and the mains voltage, an inverter making it possible to transform this direct voltage in particular alternating voltage with variable amplitude and duty cycle, then rectified to obtain monopolar pulses at high voltage of the order of 300 to 1500 V and at high frequency of the order of 100 Hz to 10 K Hertz which supply the oven.
  • the two types of heating can be used independently, alternately or even simultaneously during the treatment (heating means specific to the oven and operation in hot plasma mode).

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Plasma Technology (AREA)
  • Physical Vapour Deposition (AREA)
  • Chemical Vapour Deposition (AREA)

Abstract

Apparatus for thermochemical treatment of metals with accurate control of the treatment temperature in a furnace having a structure similar to that of a classic furnace for thermal or thermochemical treatment in a rarified atmosphere, equipped with a controlled heater, and possibly a cooler, an anode, and a cathode supporting the pieces to be treated. A cold plasma is generated around the pieces to be treated by applying between the anode and the cathode a pulse train at a relatively high frequency and of very short pulse width in relation to pulse repetition rate.

Description

La présente invention concerne un procédé de traitements thermochimiques de métaux tels que la nitruration, la carbonitruration, la cémentation, les dépôts métalliques sous vide, etc... par bombardement ionique.The present invention relates to a process for thermochemical treatments of metals such as nitriding, carbonitriding, carburizing, metallic deposits under vacuum, etc. by ion bombardment.

D'une manière générale, on sait que ces traitements font intervenir deux facteurs principaux, à savoir le milieu de traitement et la température de traitement.Generally, it is known that these treatments involve two main factors, namely the treatment medium and the treatment temperature.

Ainsi, par exemple, dans le cas d'un traitement classique de nitruration, le milieu de traitement peut être obtenu en faisant passer sur les pièces un courant de gaz ammoniac, qui, en se décomposant, libère des atomes d'azote actifs. La température de traitement qui est de l'ordre de 570°C est alors obtenue en disposant les pièces dans un four électrique.Thus, for example, in the case of a conventional nitriding treatment, the treatment medium can be obtained by passing a stream of ammonia gas over the parts, which, when decomposed, releases active nitrogen atoms. The treatment temperature which is of the order of 570 ° C. is then obtained by placing the parts in an electric oven.

Dans le cas d'un traitement de nitruration par bombardement ionique, les pièces à traiter sont disposées dans une enceinte contenant un gaz (NH3, azote moléculaire, H2 CH4) à basse pression (0,1 à 10 torrs). Cette enceinte est équipée d'une anode et d'une cathode, reliées à un générateur de courant électrique à haute tension (entre 300 et 1500 V). La cathode est conçue de manière à supporter les pièces à traiter qui se trouvent, par conséquent, portées au cathodique.In the case of a nitriding treatment by ion bombardment, the parts to be treated are placed in an enclosure containing a gas (NH 3 , molecular nitrogen, H 2 CH 4 ) at low pressure (0.1 to 10 torr). This enclosure is equipped with an anode and a cathode, connected to a high voltage electric current generator (between 300 and 1500 V). The cathode is designed so as to support the parts to be treated which are therefore brought to the cathode.

Le traitement s'obtient en créant, entre la cathode et l'anode, une décharge luminescente que l'on entretient à la limite du régime d'arc.The treatment is obtained by creating, between the cathode and the anode, a luminescent discharge which is maintained at the limit of the arc regime.

Au cours de ce traitement, il se crée, autour de la pièce à traiter, un plasma composé d'ions azote qui constitue en fait le milieu de traitement.During this treatment, a plasma is created around the part to be treated, composed of nitrogen ions which in fact constitutes the treatment medium.

La température de traitement est alors obtenue par la dissipation calorifique engendrée par le bombardement des ions sur la pièce (énergie cinétique).The treatment temperature is then obtained by the heat dissipation generated by the bombardment of the ions on the part (kinetic energy).

Les avantages des procédés de traitement thermochimique par bombardement ionique par rapport aux autres procédés classiques sont bien connus.The advantages of thermochemical treatment methods by ion bombardment compared to other conventional methods are well known.

Par contre, cette technique se heurte à de nombreuses difficultés parmi lesquelles on mentionnera :

  • L'imposibilité d'obtenir une bonne homogénéité de la température des pièces à traiter du fait que l'on utilise le plasma comme moyen de chauffage
    • - la difficulté de réaliser des systèmes de rupture d'arc dans le cas de générateurs de haute puissance ;
    • - la difficulté de contrôler la température des pièces en raison du fait que c'est le plasma lui-même qui effectue le chauffage des pièces ;
    • - la nécessité de ne nitrurer simultanément que des pièces de géométrie très voisines, la température n'étant pas homogène dans le cas de pièces de formes différentes.
On the other hand, this technique encounters many difficulties among which we will mention:
  • The impossibility of obtaining a good homogeneity of the temperature of the parts to be treated due to the fact that the plasma is used as a heating means
    • - the difficulty of producing arc breaking systems in the case of high power generators;
    • - the difficulty of controlling the temperature of the rooms due to the fact that it is the plasma itself which performs the heating of the rooms;
    • - The need to nitride simultaneously only parts of very similar geometry, the temperature not being uniform in the case of parts of different shapes.

Pour supprimer tous ces inconvénients, de nombreuses solutions ont été étudiées.To overcome all these drawbacks, numerous solutions have been studied.

Ainsi, pour tenter de résoudre ces problèmes, on a proposé d'inclure dans l'enceinte du four un dispositif de chauffage destiné à préchauffer la pièce ou pour fournir un apport calorifique au cours du traitement. Toutefois, une telle solution ne permet pas, dans le cas d'une alimentation classique des électrodes du four, le contrôle efficace de la température des pièces, et une bonne homogénéité de leur température.Thus, in an attempt to solve these problems, it has been proposed to include in the enclosure of the oven a heating device intended to preheat the room or to provide a calorific contribution during the treatment. However, such a solution does not allow, in the case of a conventional supply of the oven electrodes, effective control of the temperature of the parts, and good uniformity of their temperature.

Une autre solution envisagée pour obtenir un fonctionnement exempt du risque de formation d'arcs consiste à utiliser, au lieu d'un courant continu, des impulsions de courant à haute tension, mais dont l'énergie totale est maintenue à une valeur prédéterminée, de manière à ce qu'il ne soit pas possible d'atteindre, dans la courbe de décharge tension/intensité, la zone correspondant au régime d'arc.Another solution envisaged for obtaining an operation free from the risk of arcing consists in using, instead of direct current, high-voltage current pulses, but the total energy of which is maintained at a predetermined value, of so that it is not possible to reach, in the voltage / current discharge curve, the zone corresponding to the arc speed.

Selon cette technique, pour parvenir à élever la température des pièces jusqu'à la température de traitement ou même pour assurer le maintien de cette température dans le cas où les pièces ont été préchauffées, il est nécessaire de prévoir des impulsions relativement larges par rapport à la période.According to this technique, in order to raise the temperature of the parts to the treatment temperature or even to maintain this temperature in the case where the parts have been preheated, it is necessary to provide relatively large pulses compared to the period.

Il a'avère toutefois que cette solution ne permet pas elle non plus d'obtenir une bonne homogénéité de température des pièces.It turns out, however, that this solution does not allow also not to obtain a good homogeneity of temperature of the parts.

Dans le but de supprimer tous ces inconvénients l'invention propose de rendre totalement indépendant les 2 paramètres du traitement à savoir la réalisation du milieu de traitement, c'est-à-dire du plasma, et le chauffage à la température de traitement des pièces.With the aim of eliminating all these drawbacks, the invention proposes to make the 2 parameters of the treatment completely independent, namely the production of the treatment medium, that is to say the plasma, and the heating to the treatment temperature of the parts. .

A cet effet, elle utilise les propriétés relatives au temps de génération du plasma et à sa durée de vie (rémanence). On sait qu'un plasma généré par une impulsion de courant à haute tension se maintient pendant un temps relativement long (quelques centaines de microsecondes à quelques millisecondes) par rapport au temps de génération de ce plasma (quelques microsecondes).For this purpose, it uses the properties relating to the time of generation of the plasma and to its lifetime (persistence). It is known that a plasma generated by a high voltage current pulse is maintained for a relatively long time (a few hundred microseconds to a few milliseconds) relative to the generation time of this plasma (a few microseconds).

En conséquence, en créant une succession d'impulsions à fréquence élevée (la période de ces impulsions pouvant avoisiner la durée de vie du plasma, c'est-à-dire de 100 microsecondes à 10 millisecondes), et de durée très brève, entre 1 à 100 microsecondes (supérieure au temps de création du plasma, on obtient de façon continue un plasma froid, c'est-à-dire un plasma dans lequel l'énergie calorifique dissipée au cours de la dissociation demeure à un niveau très bas et ne peut pas affecter les caractéristiques de température du traitement en cours, dans le cas d'un traitement thermochimique.Consequently, by creating a succession of pulses at high frequency (the period of these pulses being able to approach the lifetime of the plasma, that is to say from 100 microseconds to 10 milliseconds), and of very brief duration, between 1 to 100 microseconds (greater than the plasma creation time, a cold plasma is obtained continuously, that is to say a plasma in which the heat energy dissipated during the dissociation remains at a very low level and cannot affect the temperature characteristics of the treatment in progress, in the case of a thermochemical treatment.

D'une façon plus précise, le procédé de traitement thermique selon l'invention fait intervenir un four de structure analogue à celle d'un four classique de traitement thermique ou thermochimique à atmosphère raréfiée équipé de ses propres moyens de chauffage et de contrôle et comprenant en outre au moins une anode et une cathode supportant les pièces à traiter. Il consiste à générer sur les pièces à traiter un plasma froid tel que précédemment défini en établissant entre l'anode et la cathode une succession d'impulsions de tension à fréquence relativement élevée et de durée très brève et, à chauffer les pièces à l'aide des susdits moyens de chauffage, de manière à les porter puis à les maintenir à la température de traitement.More precisely, the heat treatment method according to the invention involves an oven with a structure similar to that of a conventional heat or thermochemical treatment oven with a rarefied atmosphere equipped with its own heating and control means and comprising furthermore at least one anode and one cathode supporting the parts to be treated. It consists in generating on the workpieces a cold plasma as defined above by establishing between the anode and the cathode a succession of voltage pulses at relatively high frequency and duration very brief and to heat the parts using the above heating means, so as to bring them then to maintain them at the processing temperature.

Ce procédé présente de multiple avantages :

  • - Du fait que le chauffage des pièces est indépendant de la génération du plasma, il est possible d'utiliser des générateurs d'impulsion de puissance très faible par rapport à celle qui serait autrement nécessaire.
  • - La température de traitement peut être facilement contrôlée et de façon précise, en utilisant les équipements éprouvés des fours de traitement thermique ou thermochimiques classiques.
  • - Le contrôle des autres paramètres de traitement est facilité du fait que l'on peut jouer simultanément sur le rapport cyclique, l'amplitude et la fréquence des impulsions ; et
  • - Le risque de détérioration des pièces par formation d'arc est totalement supprimé du fait que le plasma est généré par des impulsions de courte durée.
This process has multiple advantages:
  • - Because the heating of the rooms is independent of the generation of the plasma, it is possible to use pulse generators of very low power compared to that which would otherwise be necessary.
  • - The treatment temperature can be easily and precisely controlled, using the proven equipment of conventional heat or thermochemical treatment furnaces.
  • - The control of the other processing parameters is facilitated by the fact that one can simultaneously play on the duty cycle, the amplitude and the frequency of the pulses; and
  • - The risk of deterioration of the parts by arcing is completely eliminated because the plasma is generated by short-duration pulses.

Ce procédé permet en outre de supprimer les hétérogénéités de température en fonction des paramètres liés aux pièces tels que la forme, l'état, les phénomènes de cathode creuse pendant la montée en température, les dimensions de pièces différentes, etc...This method also makes it possible to remove the temperature heterogeneities as a function of the parameters linked to the parts such as the shape, the state, the hollow cathode phenomena during the rise in temperature, the dimensions of different parts, etc.

L'invention concerne également une installation pour le traitement thermochimique par bombardement ionique appliquant le procédé selon l'invention.The invention also relates to an installation for thermochemical treatment by ion bombardment applying the method according to the invention.

Comme précédemment mentionné, cette installation fait intervenir un four présentant une structure analogue à celle d'un four classique de traitement thermique ou thermochimique à atmosphère raréfiée, ce four comprenant ses propres moyens de chauffage, par convexion,par rayonnement, cohérent ou non,ou par induction, ses propres moyens de régulation, un générateur de gaz de traitement et des passages de courant traversant la paroi du four et connectés aux électrodes (anodes- cathodes) servant à la génération du plasma.As previously mentioned, this installation involves an oven having a structure similar to that of a conventional heat or thermochemical treatment oven with a rarefied atmosphere, this oven comprising its own heating means, by convection, by radiation, coherent or not, or by induction, its own regulation means, a generator of process gas and current passages passing through the wall of the furnace and connected to the electrodes (anodes-cathodes) used for the generation of the plasma.

L'alimentation de ces électrodes peut-8tre assurée à partir du roseau triphasé ou monophasé industriel au moyen d'un générateur comprenant un redresseur contrôlé permettant d'obtenir une tension continue variable entre O et la tension du secteur, un onduleur permettant de transformer cette tension continue en tension alternative particulière à amplitude et à rapport cyclique variables, puis redressée pour obtenir des impulsions monopolaires à haute tension de l'ordre de 300 à 1500 V et à fréquence élevée de l'ordre de 100 Hz à 10 K Hertz qui alimentent le four.The supply of these electrodes can be provided from the three-phase or single-phase industrial reed by means of a generator comprising a controlled rectifier making it possible to obtain a variable DC voltage between 0 and the mains voltage, an inverter making it possible to transform this direct voltage in particular alternating voltage with variable amplitude and duty cycle, then rectified to obtain monopolar pulses at high voltage of the order of 300 to 1500 V and at high frequency of the order of 100 Hz to 10 K Hertz which supply the oven.

On notera que l'adoption d'un générateur de plasma de grande puissance et basé sur un même principe permet d'obtenir un fonctionnement mixte, plasma chaud, plasma froid.It will be noted that the adoption of a high power plasma generator based on the same principle makes it possible to obtain mixed operation, hot plasma, cold plasma.

De même, dans ce cas, on peut utiliser indépendamment, alternativement ou même simultanément au cours du traitement, les deux types de chauffage (moyens de chauffage propres au four et fonctionnement en mode plasma chaud).Likewise, in this case, the two types of heating can be used independently, alternately or even simultaneously during the treatment (heating means specific to the oven and operation in hot plasma mode).

Claims (8)

1.- Procédé de traitements thermochimiques de métaux par bombardement ionique faisant intervenir un four de structure analogue à celle d'un four classique de traitement thermique ou thermochimique à atmosphère raréfiée, équipé de ses propres moyens de chauffage et de contrôle et, éventuellement, de refroidissement et comprenant en outre au moins une anode et une cathode supportant les pièces à traiter, caractérisé en ce qu'il consiste à générer sur les pièces à traiter un plasma froid en établissant entre l'anode et la cathode une succession d'impulsions de courant de fréquence relativement élevée (période inférieure à la durée de vie du plasma) et de durée très brève par rapport à la période, (durée supérieure à la durée de génération du plasma) et à chauffer les pièces à l'aide des susdits moyens de chauffage, de manière à les porter puis à les maintenir à la température de traitement.1.- Method of thermochemical treatment of metals by ion bombardment involving a furnace with a structure similar to that of a conventional furnace for thermal or thermochemical treatment with rarefied atmosphere, equipped with its own heating and control means and, optionally, cooling and further comprising at least one anode and a cathode supporting the parts to be treated, characterized in that it consists in generating on the parts to be treated a cold plasma by establishing between the anode and the cathode a succession of pulses of current of relatively high frequency (period less than the lifetime of the plasma) and of very short duration compared to the period, (duration greater than the duration of generation of the plasma) and to heat the parts using the above means heating, so as to bring them then to maintain them at the processing temperature. 2.- Procédé selon la revendication 1, caractérisé en ce que l'amplitude, la fréquence et la durée des impulsions sont variables.2.- Method according to claim 1, characterized in that the amplitude, frequency and duration of the pulses are variable. 3.- Procédé selon l'une des revendications 1 et 2, caractérisé en ce qu'il utilise un générateur d'impulsions permettant, en jouant sur l'amplitude, la fréquence et/ou la durée des impulsions, d'obtenir un fonctionnement mixte, plasma froid, plasma chaud.3.- Method according to one of claims 1 and 2, characterized in that it uses a pulse generator allowing, by playing on the amplitude, frequency and / or duration of the pulses, to obtain an operation mixed, cold plasma, hot plasma. 4.- Procédé selon l'une des revendications précédentes, caractérisé en ce que l'on utilise indépendamment, alternativement, ou même simultanément, au cours du traitement, le chauffage obtenu par les susdits moyens de chauffage et le chauffage obtenu par le fonctionnement en mode plasma chaud.4.- Method according to one of the preceding claims, characterized in that one uses independently, alternately, or even simultaneously, during treatment, the heating obtained by the above heating means and the heating obtained by the operation in hot plasma mode. 5.- Procédé selon l'une des revendications précédentes, caractérisé en ce que la fréquence des susdites impulsions est comprise entre 100 Hz et 10 K Hertz.5.- Method according to one of the preceding claims, characterized in that the frequency of the above pulses is between 100 Hz and 10 K Hertz. 6.- Procédé selon l'une des revendications précédentes, caractérisé en ce qu'en fonctionnement en mode plasma froid, la durée des impulsions peut varier entre 1 à 100 microsecondes, et en ce que la période des impulsions varie de 100 microsecondes à 10 millisecondes.6.- Method according to one of the preceding claims, characterized in that in operation in mode cold plasma, the pulse duration can vary between 1 to 100 microseconds, and in that the pulse period varies from 100 microseconds to 10 milliseconds. 7.- Installation pour le traitement thermochimique par bombardement ionique conformément au procédé selon l'une des revendications précédentes, caractérisée en ce qu'elle comprend un four présentant une structure analogue à celle d'un four classique de traitement thermique ou thermochimique à atmosphère raréfiée, ce four comportant ses propres moyens de chauffage par convexion ou par rayonnement, ses propres moyens de régulation, un générateur de gaz de traitement et des passages de courant traversant la paroi du four et prévus pour relier les électrodes servant à la génération du plasma à un générateur délivrant des impulsions à haute tension, à une fréquence réglable de 100 Hz à 10 K Hertz et à largeur d'impulsions réglable de 1 à 100 microsecondes.7.- Installation for thermochemical treatment by ion bombardment in accordance with the method according to one of the preceding claims, characterized in that it comprises an oven having a structure similar to that of a conventional heat or thermochemical treatment oven with rarefied atmosphere , this furnace having its own means of heating by convection or by radiation, its own regulation means, a generator of process gas and current passages passing through the wall of the furnace and provided for connecting the electrodes used for the generation of plasma to a generator delivering pulses at high voltage, at a frequency adjustable from 100 Hz to 10 K Hertz and at pulse width adjustable from 1 to 100 microseconds. 8.- Installation selon la revendication 7, caractérisée en ce que le susdit générateur fonctionne à partir du réseau triphasé ou monophasé industriel et comprend un redresseur contrôlé permettant d'obtenir une tension continue variable entre O et la tension du secteur, un onduleur permettant de transformer cette tension continue en une tension alternative à amplitude et rapport cyclique variables puis redressée pour obtenir des impulsions monopolaires à une tension de l'ordre de 300 à 1500 Volts et une fréquence de l'ordre de 100 Hz à 10 K Hz.8.- Installation according to claim 7, characterized in that the above generator operates from the three-phase or single-phase industrial network and comprises a controlled rectifier making it possible to obtain a variable DC voltage between O and the mains voltage, an inverter making it possible to transform this DC voltage into an AC voltage with variable amplitude and duty cycle then rectified to obtain monopolar pulses at a voltage of the order of 300 to 1500 Volts and a frequency of the order of 100 Hz to 10 K Hz.
EP82400407A 1981-03-13 1982-03-09 Process for the thermochemical treatments of metals by ion bombardment Expired EP0062550B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT82400407T ATE37907T1 (en) 1981-03-13 1982-03-09 PROCESSES FOR THE THERMOCHEMICAL TREATMENTS OF METALS BY ION Bombardment.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8105107 1981-03-13
FR8105107A FR2501727A1 (en) 1981-03-13 1981-03-13 PROCESS FOR THE THERMOCHEMICAL TREATMENT OF METALS BY ION BOMBING

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DE3322341A1 (en) * 1983-06-22 1985-01-03 Siegfried Dr.-Ing. 5135 Selfkant Strämke METHOD AND DEVICE FOR THE SURFACE TREATMENT OF WORKPIECES BY GLIMMER DISCHARGE
WO1987001738A1 (en) * 1985-09-24 1987-03-26 Centre National De La Recherche Scientifique (Cnrs Method and device for chemical treatment, particularly thermochemical treatment and chemical deposition in a large volume homogeneous plasma
FR2600082A1 (en) * 1986-06-13 1987-12-18 Balzers Hochvakuum THERMO-CHEMICAL PROCESS FOR SURFACE TREATMENT IN REACTIVE GAS PLASMA, AND PARTS PROCESSED THEREBY
DE3700633C1 (en) * 1987-01-12 1988-05-26 Reinar Dr Gruen Method and device for the gentle coating of electrically conductive objects by means of plasma
EP0269251A1 (en) * 1986-10-29 1988-06-01 The Electricity Council Method and apparatus for thermochemical treatment
EP0552460A1 (en) * 1992-01-20 1993-07-28 Leybold Durferrit GmbH Process for hardening of work pieces unter the action of plasma-pulses
FR2689976A1 (en) * 1992-04-14 1993-10-15 Innovatique Sa Reactive gas mixt. compsn. determn. and control for thermochemical treatment - by spectrometrically analysing luminous radiation emitted by plasma generation of ionic bombardment, and measuring spectral ray characteristic intensity
US5346560A (en) * 1991-07-16 1994-09-13 Centre Stephanois De Recherches Mecaniques Hydromecanique Et Frottement Process for the treatment of ferrous metal parts to improve their corrosion resistance and friction properties simultaneously
US5833918A (en) * 1993-08-27 1998-11-10 Hughes Electronics Corporation Heat treatment by plasma electron heating and solid/gas jet cooling
US5948224A (en) * 1992-03-24 1999-09-07 Balzers Aktiengsellschaft Method of controlling a treatment process and vacuum treatment apparatus
US6504690B2 (en) 1998-04-30 2003-01-07 Hitachi, Ltd. Spin-tunnel magneto-resistance type magnetic sensor

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Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3322341A1 (en) * 1983-06-22 1985-01-03 Siegfried Dr.-Ing. 5135 Selfkant Strämke METHOD AND DEVICE FOR THE SURFACE TREATMENT OF WORKPIECES BY GLIMMER DISCHARGE
WO1987001738A1 (en) * 1985-09-24 1987-03-26 Centre National De La Recherche Scientifique (Cnrs Method and device for chemical treatment, particularly thermochemical treatment and chemical deposition in a large volume homogeneous plasma
FR2587729A1 (en) * 1985-09-24 1987-03-27 Centre Nat Rech Scient METHOD AND DEVICE FOR CHEMICAL TREATMENT, IN PARTICULAR THERMOCHEMICAL TREATMENT AND CHEMICAL DEPOSIT IN A HOMOGENEOUS PLASMA OF LARGE VOLUME
FR2600082A1 (en) * 1986-06-13 1987-12-18 Balzers Hochvakuum THERMO-CHEMICAL PROCESS FOR SURFACE TREATMENT IN REACTIVE GAS PLASMA, AND PARTS PROCESSED THEREBY
EP0269251A1 (en) * 1986-10-29 1988-06-01 The Electricity Council Method and apparatus for thermochemical treatment
DE3700633C1 (en) * 1987-01-12 1988-05-26 Reinar Dr Gruen Method and device for the gentle coating of electrically conductive objects by means of plasma
US5346560A (en) * 1991-07-16 1994-09-13 Centre Stephanois De Recherches Mecaniques Hydromecanique Et Frottement Process for the treatment of ferrous metal parts to improve their corrosion resistance and friction properties simultaneously
EP0552460A1 (en) * 1992-01-20 1993-07-28 Leybold Durferrit GmbH Process for hardening of work pieces unter the action of plasma-pulses
US5948224A (en) * 1992-03-24 1999-09-07 Balzers Aktiengsellschaft Method of controlling a treatment process and vacuum treatment apparatus
US6878248B2 (en) 1992-03-24 2005-04-12 Hans Signer Method of manufacturing an object in a vacuum recipient
FR2689976A1 (en) * 1992-04-14 1993-10-15 Innovatique Sa Reactive gas mixt. compsn. determn. and control for thermochemical treatment - by spectrometrically analysing luminous radiation emitted by plasma generation of ionic bombardment, and measuring spectral ray characteristic intensity
US5833918A (en) * 1993-08-27 1998-11-10 Hughes Electronics Corporation Heat treatment by plasma electron heating and solid/gas jet cooling
US5868878A (en) * 1993-08-27 1999-02-09 Hughes Electronics Corporation Heat treatment by plasma electron heating and solid/gas jet cooling
US6504690B2 (en) 1998-04-30 2003-01-07 Hitachi, Ltd. Spin-tunnel magneto-resistance type magnetic sensor

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JPS57210971A (en) 1982-12-24
EP0062550B1 (en) 1988-10-12
FR2501727A1 (en) 1982-09-17
US4672170A (en) 1987-06-09
DE3279106D1 (en) 1988-11-17
US4490190A (en) 1984-12-25
ATE37907T1 (en) 1988-10-15
FR2501727B1 (en) 1983-06-03

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