EP1032022B1 - Metal halide lamp with ceramic discharge vessel - Google Patents

Metal halide lamp with ceramic discharge vessel Download PDF

Info

Publication number
EP1032022B1
EP1032022B1 EP00100687A EP00100687A EP1032022B1 EP 1032022 B1 EP1032022 B1 EP 1032022B1 EP 00100687 A EP00100687 A EP 00100687A EP 00100687 A EP00100687 A EP 00100687A EP 1032022 B1 EP1032022 B1 EP 1032022B1
Authority
EP
European Patent Office
Prior art keywords
cermet
ceramic
halide lamp
rare
metal halide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP00100687A
Other languages
German (de)
French (fr)
Other versions
EP1032022A1 (en
Inventor
Reiner-Joachim Dr. Dinter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Osram GmbH
Original Assignee
Patent Treuhand Gesellschaft fuer Elektrische Gluehlampen mbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Patent Treuhand Gesellschaft fuer Elektrische Gluehlampen mbH filed Critical Patent Treuhand Gesellschaft fuer Elektrische Gluehlampen mbH
Publication of EP1032022A1 publication Critical patent/EP1032022A1/en
Application granted granted Critical
Publication of EP1032022B1 publication Critical patent/EP1032022B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01JELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00Gas-discharge or vapour-discharge lamps
    • H01J61/02Details
    • H01J61/36Seals between parts of vessels; Seals for leading-in conductors; Leading-in conductors

Definitions

  • the invention is based on a metal halide lamp with a ceramic discharge vessel according to the preamble of claim 1. It is in particular around metal halide lamps with an output of at least 100 W.
  • a generic metal halide lamp with a ceramic discharge vessel and a halide-resistant bushing is already known from EP-A 587 238.
  • the front part of the bushing facing the discharge can consist of an electrically conductive cermet (with a ceramic and a conductive phase).
  • Aluminum oxide or also MgO, Sc 2 O 3 or Y 2 O 3 is used as the ceramic phase.
  • a halogen-resistant metal, for example tungsten, or molybdenum disilicide (MoSi 2 ) is proposed as the conductive phase of the cermet.
  • Filling components made from rare earth metal halides (SE) are usually used in these lamps.
  • DyJ 3 is recommended.
  • the use of the iodides of Sc, Y, Ho or Tm is recommended.
  • EP-A 887 839 recommends using a continuous cermet stick to be used for metal halide lamps with ceramic discharge tube.
  • the starting point of the present invention is the discovery that due to the high temperature in the area of the end face of the binding carrying out Rare earth metal ions from the filling preferably in the region of a front zone Implementation takes place, at least the surface of the part of the implementation that with is in contact with the discharge volume. Most of them are the frontal discharge end of the bushing since it is the highest temperature reached in operation. In contrast, the discharge vessel itself and the sealant (usually a stopper) significantly less affected.
  • the front part is a cermet component with a ceramic and an electrically conductive Phase.
  • the ceramic phase of the cermet component contains the ceramic phase of the cermet component, either the entire one Component or a zone on the surface facing the discharge from from the outset a considerable proportion (especially at least 40, especially more than 80 mol%) of a corresponding compound made of the ceramic base material and at least one rare earth oxide, the cermet component or its zone exposed to discharge, no longer bind rare earth metal from the filling. Therefore, the filling and thus the maintenance of the lamp over a long service life stable without using an overdose of the filling got to.
  • the surface with a garnet or perovskite structure can be on the front and possibly also on the lateral surface of the cermet component.
  • the invention is a metal halide lamp ceramic discharge vessel, the discharge vessel having two ends which are closed with means for sealing.
  • one electrically conductive bushing passed vacuum-tight, on the one electrode is fastened with a shaft which projects into the interior of the discharge vessel.
  • At least one front part of the feedthrough that faces the discharge is designed as a halide-resistant component made of electrically conductive cermet, that of an electrically conductive (especially metallic) and a ceramic Phase, which comprises a ceramic base material.
  • the filling comprises at least a rare earth metal (i.e. Sc, Y, La and the 14 lanthanoids), mostly as a halide, or as a complex or elementary.
  • At least on the face (Front) of the component consists of at least part of the ceramic phase Connection of the ceramic base material with one or more rare earth oxides.
  • the cermet component is preferably a pin or a tube.
  • the cermet usually has a metal such as molybdenum or tungsten or rhenium or their alloys or a metal silicide such as MoSi 2 as the electrically conductive phase.
  • the safest is when it covers the entire area Length of the component at least part of the ceramic phase from the connection of the ceramic base material with one or more rare earth oxides consists.
  • the entire ceramic phase preferably consists of the connection of the ceramic base material and one or more rare earth oxides.
  • the Cermet component can carry out the front part or the whole Form implementation.
  • the ceramic base material is usually polycrystalline aluminum oxide.
  • those used for the cermet component include Rare earth metal oxides are the oxides of one or more or all of them in the filling contained rare earth metals.
  • the rare earth oxides comprise the oxides of one or more rare earth metals not contained in the filling, in particular Y 2 O 3 .
  • Embodiment corresponds to the connection of the ceramic base material with one or more rare earth oxides Garnet or perovskite or a mixture of both.
  • a perovskite preferably oxides of La, Nd, Sm, Eu or Gd are used.
  • oxides of Lu, Yb, Tm and Y are particularly suitable for both structures and their mixtures.
  • This special cermet component is used in all metal halide lamps possible with ceramic discharge vessel, regardless of whether the seal by means of melting ceramics or by direct sintering.
  • the production of the special cermet can be carried out in a manner known per se by processing an appropriate powder mixture.
  • the basic Suitability of such materials (especially yttrium aluminum garnet) for the lamp construction is already known, see US-A 5 698 948. There the material however used for discharge vessels. The requirement of Translucency does not matter in the implementation.
  • the means for sealing (usually a stopper) advantageously consists of ceramic or Cermet (for example, suitably doped aluminum oxide), the ceramic Base material of the cermet component is a ceramic main component of the agent corresponds to sealing, here aluminum oxide.
  • This arrangement has the advantage that the thermal expansion coefficients of both parts are similar, so that a direct sintering of the cermet component in the stopper is particularly successful.
  • a metal halide lamp with an output of 250 W is shown schematically in FIG. It consists of a cylindrical outer bulb 1 made of quartz glass which defines a lamp axis and is squeezed (2) and base (3) on two sides.
  • the axially arranged discharge vessel 4 made of Al 2 O 3 ceramic is bulged in the middle 5 and has two cylindrical ends 6a and 6b. It is held in the outer bulb 1 by means of two power leads 7, which are connected to the base parts 3 via foils 8.
  • the power supply lines 7 are welded to bushings 9, 10 which are each fitted in an end plug 11 at the end of the discharge vessel.
  • the bushings 9, 10 are cermet pins with a diameter of approx. 1 mm, which consist of an electrically conductive cermet.
  • Both bushings 9, 10 extend over the entire length of the plug 11 and hold electrodes 14 on the discharge side, consisting of an electrode shaft 15 made of tungsten and one pushed on at the discharge end Spiral 16.
  • the bushing 9, 10 is in each case with the electrode shaft 15 and butt welded to the external power supply 7.
  • the discharge vessel is filled with an inert ignition gas, e.g. Argon, and possibly mercury from additions to metal halides, thereof at least one rare earth metal.
  • an inert ignition gas e.g. Argon
  • mercury from additions to metal halides, thereof at least one rare earth metal.
  • End plugs 11 are used as means for sealing, which essentially consist of Al 2 O 3 , for example. It is also possible to use a non-conductive cermet with the main component Al 2 O 3 , with tungsten being present as a metallic component in a proportion of approximately 30% by weight (or molybdenum with a correspondingly higher proportion).
  • the bushing 9, 10 is sintered directly into the plug 11. More like that The plug 11 is also in each case in the cylindrical end 6 of the discharge vessel sintered directly (i.e. without glass solder or melting ceramic).
  • an axially parallel bore 12 in the plug 11 provided for evacuating and filling the discharge vessel in a known manner Way serves.
  • This bore 12 is made after filling by means of a pin 13 or closed by means of melting ceramic.
  • the pen usually consists of Ceramics or cermet.
  • a cermet pen is suitable as bushing 9, 10, which in addition to ceramic phase with the base material aluminum oxide at least 44 vol .-% Contains metal (preferably between 45 and 75 vol .-%) and is electrically conductive. In particular 70 to 90% by weight of tungsten or 55 to 80% by weight of molybdenum is suitable (or an amount of rhenium equivalent in volume).
  • the ceramic Phase consists entirely of garnet (see below).
  • a cermet with a lower percentage is suitable as the material for the end plug of metal as the feedthrough (preferably about half the proportion in the Implementation) contains.
  • An essential property of the plug is that coefficient of thermal expansion between that of implementation and that of Discharge vessel is.
  • the metal content of the stopper can also be zero.
  • the electrode is welded to the end face of the bushing before the bushing is sintered into the stopper.
  • the weldable cermet pin is largely pre-sintered before it is finally sintered.
  • the proportion of rare earth metal ions was accordingly in the filling at the beginning: Dy 3+ 5.8% and Ho 3+ 5.9% and Tm 3+ 6.0%.
  • the rare earth ion with the smallest effective ion radius namely Tm (about 0.088 nm ion radius, see Fig. 2), accumulated significantly more than the other two: Dy 3+ 15.2% by weight; Ho 3+ 18.4 wt% and Tm 3+ 26.8 wt%.
  • cermet component was used, that from the outset as the ceramic phase, for example the natural one Equilibrium distribution used and thus anticipates this diffusion process:
  • a regular garnet was used as the ceramic phase for this cermet component, using only Tm 2 O 3 as the rare earth oxide with aluminum oxide as the base material.
  • Sc 2 O 3 (or also Yb 2 O 3 ) is used as the rare earth metal oxide. Both ions have a smaller ion radius (0.075 or 0.087 nm) than the rare earth metal ions used in the filling. The life span achieved in this way corresponds approximately to that of the second exemplary embodiment.
  • a second embodiment is at the ends of the approximately circular cylindrical Discharge vessel 25 each sintered a non-conductive plug 26 directly.
  • the implementation is an electrically conductive cermet pin 9, 10 with a Metal content of 50% by volume.
  • the rest is a ceramic phase.
  • the plug 26 out Aluminum oxide consists of two concentric parts, an outer annular one Plug part 21 and an inner, about twice as long capillary tube 20. Nevertheless the capillary tube is about 50% compared to known capillary tube techniques , shorter.
  • the large length of the capillary tube compared to the plug part 21 improved the sealing behavior.
  • the cermet pin 9 is recessed in the capillary tube 20 and sintered there directly.
  • the filling bore 22 is in the outer plug part 21 accommodated.
  • an Eu 2 O 3 perovskite structure is used as the ceramic phase only on its end face 19 over an axial length of approximately 1 mm, which gradually changes into the known structure with a pure aluminum oxide phase in a subsequent transition zone, which is used at the end of the pen.
  • Figure 4 shows a cermet pin 27, which is composed of two parts.
  • the front front part 28 has a garnet structure as a ceramic phase with aluminum oxide as the base material and Er 2 O 3 as the rare earth oxide. It has an axial nose 29 with which it is fitted into a circular cylindrical bore of an extension part 30 arranged behind it. Both parts are connected by direct sintering.
  • both parts of the cermet pin 31, the cermets of which can be welded by the proportion of the metallic phase (Mo) being approximately 50% by volume, can be butt-welded to one another, as shown in FIG. 5.
  • the front part 32 and the extension part 33 are approximately the same length.
  • YAG yttrium aluminum garnet, 3 Y 2 O 3 • 5 Al 2 O 3
  • FIG. 6 shows a further exemplary embodiment in which the end of the cylindrical ceramic discharge vessel 40 (made of aluminum oxide) is closed by a ceramic end plate 41 and a tubular plug 42.
  • a two-part bushing 43 is sealed by means of glass solder 44 in the stopper.
  • the bushing 43 consists of a cermet pin 45 on the discharge side and a niobium pin 46 facing away from the discharge.
  • the electrode 47 is fastened to the cermet pin.
  • the surface of the cermet stick is covered by a 300 ⁇ m thick layer 48 of YAG.
  • the conductive phase (60 vol.%) Of the cermet stick consists of MoSi 2
  • the ceramic phase (rest) consists of 50 mol.% Al 2 O 3 and 50 mol.% Of a mixture of YAG and Eu 2 O 3 - perovskite.
  • the filling contains DyJ 3 and CeJ 3 as rare earth metal iodides.

Landscapes

  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Discharge Lamps And Accessories Thereof (AREA)
  • Discharge Lamp (AREA)

Abstract

A metal halide lamp with a ceramic discharge vessel, having conductive bushings comprising a cermet with a rare earth metal oxide-containing compound ceramic phase, is new. A metal halide lamp has a ceramic discharge vessel which has a filling comprising one or more rare earth metals and which is fitted with electrically conductive bushings passing vacuum-tightly through the vessel end seals. At least the discharge-facing front portion (45) of each bushing is in the form of a halide-resistant component of electrically conductive cermet comprising an electrically conductive phase and a ceramic phase which consists, at least at its surface accessible to the filling, of a compound of the ceramic base material with one or more rare earth metal oxides. Preferred Features: The cermet has a conductive phase of Mo, W, Re or their alloys or of MoSi2 and a ceramic phase of a garnet or perovskite of Al2O3 and one or more rare earth metal oxides.

Description

Technisches GebietTechnical field

Die Erfindung geht aus von einer Metallhalogenidlampe mit keramischem Entladungsgefäß gemäß dem Oberbegriff des Anspruchs 1. Es handelt sich dabei insbesondere um Metallhalogenidlampen mit einer Leistung von mindestens 100 W.The invention is based on a metal halide lamp with a ceramic discharge vessel according to the preamble of claim 1. It is in particular around metal halide lamps with an output of at least 100 W.

Stand der TechnikState of the art

Aus der EP-A 587 238 ist bereits eine gattungsgemäße Metallhalogenidlampe mit keramischem Entladungsgefäß und halogenidresistenter Durchführung bekannt. Der der Entladung zugewandte vordere Teil der Durchführung kann aus einem elektrisch leitenden Cermet (mit einer keramischen und einer leitenden Phase) bestehen. Als keramische Phase wird Aluminiumoxid oder auch MgO, Sc2O3 oder Y2O3 verwendet. Als leitende Phase des Cermets wird ein halogenresistentes Metall, beispielsweise Wolfram, oder Molybdändisilicid (MoSi2) vorgeschlagen. Üblicherweise werden bei diesen Lampen Füllungsbestandteile aus Halogeniden der Seltenerdmetalle (SE) eingesetzt. Hier ist DyJ3 empfohlen. Alternativ wird die Verwendung der Jodide des Sc, Y, Ho oder Tm empfohlen.A generic metal halide lamp with a ceramic discharge vessel and a halide-resistant bushing is already known from EP-A 587 238. The front part of the bushing facing the discharge can consist of an electrically conductive cermet (with a ceramic and a conductive phase). Aluminum oxide or also MgO, Sc 2 O 3 or Y 2 O 3 is used as the ceramic phase. A halogen-resistant metal, for example tungsten, or molybdenum disilicide (MoSi 2 ) is proposed as the conductive phase of the cermet. Filling components made from rare earth metal halides (SE) are usually used in these lamps. Here DyJ 3 is recommended. Alternatively, the use of the iodides of Sc, Y, Ho or Tm is recommended.

Die EP-A 887 839 empfiehlt, einen durchgehenden Cermet-Stift als Durchführung für Metallhalogenidlampen mit keramischem Entladungsgefäß zu verwenden.EP-A 887 839 recommends using a continuous cermet stick to be used for metal halide lamps with ceramic discharge tube.

Nachteilig an diesen Konstruktionen ist, daß bereits nach einer kurzen Betriebsdauer ein großer Teil der in der Füllung gebildeten Ionen der Seltenerdmetalle durch Reaktion mit der Keramik, meist Aluminiumoxid, gebunden wird. Daher war bisher eine deutliche Überdosierung erforderlich, was jedoch wegen der korrosiven Eigenschaften wenig erwünscht ist. Oder man mußte bei sparsamer Dosierung in Kauf nehmen, daß die Maintenance und Lebensdauer der Lampe durch Effekte wie Farbdrift und Anstieg der Brennspannung erheblich begrenzt wurde. A disadvantage of these designs is that after a short period of operation a large part of the ions of rare earth metals formed in the filling Reaction with the ceramic, usually aluminum oxide, is bound. Therefore, so far a clear overdose is necessary, however, because of the corrosive properties little is desired. Or you had to buy with economical dosage take that the maintenance and life of the lamp by effects like Color drift and increase in burning voltage was significantly limited.

Darstellung der ErfindungPresentation of the invention

Es ist Aufgabe der vorliegenden Erfindung, eine Metallhalogenidlampe mit keramischem Entladungsgefäß gemäß dem Oberbegriff des Anspruchs 1 mit verbesserter Lebensdauer bereitzustellen.It is an object of the present invention to provide a metal halide lamp with a ceramic Discharge vessel according to the preamble of claim 1 with improved Provide lifetime.

Diese Aufgabe wird durch die kennzeichnenden Merkmale des Anspruchs 1 gelöst. Besonders vorteilhafte Ausgestaltungen finden sich in den abhängigen Ansprüchen.This object is achieved by the characterizing features of claim 1. Particularly advantageous refinements can be found in the dependent claims.

Ausgangspunkt der vorliegenden Erfindung ist die Entdeckung, daß aufgrund der hohen Temperatur im Bereich der Stirnfläche der Durchführung die Bindung der Seltenerdmetallionen aus der Füllung bevorzugt im Bereich einer vorderen Zone der Durchführung erfolgt, zumindest der Oberfläche des Teils der Durchführung, der mit dem Entladungsvolumen in Kontakt steht. Ganz überwiegend handelt es sich um das frontale entladungsseitige Ende der Durchführung, da es die höchste Temperatur im Betrieb erreicht. Dagegen sind das Entladungsgefäß selbst und das Abdichtmittel (meist ein Stopfen) deutlich weniger betroffen.The starting point of the present invention is the discovery that due to the high temperature in the area of the end face of the binding carrying out Rare earth metal ions from the filling preferably in the region of a front zone Implementation takes place, at least the surface of the part of the implementation that with is in contact with the discharge volume. Most of them are the frontal discharge end of the bushing since it is the highest temperature reached in operation. In contrast, the discharge vessel itself and the sealant (usually a stopper) significantly less affected.

Daher ist es u.U. sinnvoll, die Durchführung in einen vorderen, besonders halogenidresistenten Teil und einen weniger gefährdeten hinteren Teil zu separieren. Der vordere Teil ist ein Cermet-Bauteil mit einer keramischen und einer elektrisch leitenden Phase.Therefore, it may be sensible, the implementation in a front, especially halide-resistant Part and a less endangered rear part. The front part is a cermet component with a ceramic and an electrically conductive Phase.

Eine genaue Untersuchung zeigt, daß bei der Reaktion der Seltenerdmetallionen mit der keramischen Phase des Cermet-Bauteils vorwiegend im elektrodennahen Teil des Cermets eine Verbindung entsteht, deren chemische Zusammensetzung im Falle von Aluminiumoxid als Keramik etwa einem Granat (SE3Al5O12) oder Perowskit (SEAlO3) oder einer Mischung aus beidem entspricht. Analoges gilt für andere Keramiken. Ist diese chemisch stabile Zusammensetzung nach kurzer Betriebsdauer dann erreicht, ändert sie sich nicht mehr im weiteren Verlauf der Brenndauer bzw. Lebensdauer.A precise investigation shows that during the reaction of the rare earth metal ions with the ceramic phase of the cermet component, a connection is formed predominantly in the part of the cermet near the electrode, the chemical composition of which, in the case of aluminum oxide as ceramic, is approximately a garnet (SE 3 Al 5 O 12 ) or Perovskite (SEAlO 3 ) or a mixture of both. The same applies to other ceramics. If this chemically stable composition is reached after a short period of operation, it no longer changes over the course of the burning time or service life.

Enthält nun die keramische Phase des Cermet-Bauteils, entweder das gesamte Bauteil oder eine Zone an der Oberfläche, die der Entladung zugewandt ist, von vornherein einen beträchtlichen Anteil (bev. mindestens 40, insbesondere mehr als 80 Mol.-%) einer entsprechenden Verbindung aus dem keramischen Basismaterial und mindestens einem Seltenerdmetall-Oxid, kann das Cermet-Bauteil bzw. dessen der Entladung ausgesetzte Zone, kein Seltenerdmetall aus der Füllung mehr binden. Daher ist die Füllung und damit die Maintenance der Lampe über eine lange Lebensdauer stabil, ohne daß eine Überdosierung der Füllung verwendet werden muß. Die Oberfläche mit Granat- oder Perowskitstruktur kann sich an der Frontseite und evtl. auch an der seitlichen Mantelfläche des Cermet-Bauteils befinden.Now contains the ceramic phase of the cermet component, either the entire one Component or a zone on the surface facing the discharge from from the outset a considerable proportion (especially at least 40, especially more than 80 mol%) of a corresponding compound made of the ceramic base material and at least one rare earth oxide, the cermet component or its zone exposed to discharge, no longer bind rare earth metal from the filling. Therefore, the filling and thus the maintenance of the lamp over a long service life stable without using an overdose of the filling got to. The surface with a garnet or perovskite structure can be on the front and possibly also on the lateral surface of the cermet component.

Im einzelnen handelt es sich erfindungsgemäß um eine Metallhalogenidlampe mit keramischem Entladungsgefäß, wobei das Entladungsgefäß zwei Enden besitzt, die mit Mitteln zum Abdichten verschlossen sind. Durch diese Mittel ist jeweils eine elektrisch leitende Durchführung vakuumdicht hindurchgeführt, an der eine Elektrode mit einem Schaft befestigt ist, die in das Innere des Entladungsgefäßes hineinragt. Zumindest ein vorderer Teil der Durchführung, der der Entladung zugewandt ist, ist als ein halogenidresistentes Bauteil aus elektrisch leitendem Cermet gestaltet, das aus einer elektrisch leitenden (bev. metallischen) und einer keramischen Phase, -die ein keramisches Basismaterial umfaßt, besteht. Die Füllung umfaßt mindestens ein Seltenerdmetall (also Sc, Y, La und die 14 Lanthanoide), meist als Halogenid, oder als Komplex oder auch elementar. Zumindest an der Stirnfläche (Frontseite) des Bauteils besteht zumindest ein Teil der keramischen Phase aus der Verbindung des keramischen Basismaterials mit einem oder mehreren Seltenerdmetall-Oxiden.In detail, according to the invention, it is a metal halide lamp ceramic discharge vessel, the discharge vessel having two ends which are closed with means for sealing. By these means there is one electrically conductive bushing passed vacuum-tight, on the one electrode is fastened with a shaft which projects into the interior of the discharge vessel. At least one front part of the feedthrough that faces the discharge is designed as a halide-resistant component made of electrically conductive cermet, that of an electrically conductive (especially metallic) and a ceramic Phase, which comprises a ceramic base material. The filling comprises at least a rare earth metal (i.e. Sc, Y, La and the 14 lanthanoids), mostly as a halide, or as a complex or elementary. At least on the face (Front) of the component consists of at least part of the ceramic phase Connection of the ceramic base material with one or more rare earth oxides.

Bevorzugt ist das Cermet-Bauteil ein Stift oder auch ein Rohr. Meist besitzt das Cermet als elektrisch leitende Phase ein Metall wie Molybdän oder Wolfram oder Rhenium oder deren Legierungen oder ein Metallsilicid wie MoSi2.The cermet component is preferably a pin or a tube. The cermet usually has a metal such as molybdenum or tungsten or rhenium or their alloys or a metal silicide such as MoSi 2 as the electrically conductive phase.

Am sichersten, allerdings auch am aufwendigsten ist es, wenn über die gesamte Länge des Bauteils zumindest ein Teil der keramischen Phase aus der Verbindung des keramischen Basismaterials mit einem oder mehreren Seltenerdmetall-Oxiden besteht. Bevorzugt besteht die gesamte keramische Phase aus der Verbindung des keramischen Basismaterials und einem oder mehreren Seltenerdmetall-Oxiden. Das Cermet-Bauteil kann den vorderen Teil der Durchführung oder auch die gesamte Durchführung bilden.The safest, but also the most complex, is when it covers the entire area Length of the component at least part of the ceramic phase from the connection of the ceramic base material with one or more rare earth oxides consists. The entire ceramic phase preferably consists of the connection of the ceramic base material and one or more rare earth oxides. The Cermet component can carry out the front part or the whole Form implementation.

Meist ist das keramische Basismaterial polykristallines Aluminiumoxid. The ceramic base material is usually polycrystalline aluminum oxide.

In einer ersten Ausführungsform umfassen die für das Cermet-Bauteil verwendeten Seltenerdmetalloxide die Oxide eines oder mehrerer oder auch aller in der Füllung enthaltenen Seltenerdmetalle.In a first embodiment, those used for the cermet component include Rare earth metal oxides are the oxides of one or more or all of them in the filling contained rare earth metals.

In einer zweiten Ausführungsform umfassen die Seltenerdmetalloxide die Oxide eines oder mehrerer nicht in der Füllung enthaltenen Seltenerdmetalle, insbesondere Y2O3.In a second embodiment, the rare earth oxides comprise the oxides of one or more rare earth metals not contained in the filling, in particular Y 2 O 3 .

In einer dritten Ausführungsform wird eine Mischung der beiden ersten Ausführungsformen verwendet.In a third embodiment, a mixture of the two first embodiments used.

In einer besonders bevorzugten. Ausführungsform entspricht, die Verbindung des keramischen Basismaterials mit einem oder mehreren Seltenerdmetall-Oxiden einem Granat oder Perowskit oder einer Mischung aus beiden. Als Perowskit werden bevorzugt Oxide des La, Nd, Sm, Eu oder Gd eingesetzt. Als Granat lassen sich insbesondere Oxide des Lu, Yb, Tm und Y einsetzen. Die restlichen Seltenerdmetall-Oxide sind für beide Strukturen und deren Mischungen besonders gut geeignet.In a particularly preferred. Embodiment corresponds to the connection of the ceramic base material with one or more rare earth oxides Garnet or perovskite or a mixture of both. As a perovskite preferably oxides of La, Nd, Sm, Eu or Gd are used. As a garnet especially use oxides of Lu, Yb, Tm and Y. The remaining rare earth oxides are particularly suitable for both structures and their mixtures.

Besonders einfach und effektiv ist es, als Seltenerdmetall-Oxid überwiegend oder ausschließlich ein Oxid eines Seltenerdmetalls mit möglichst kleinem Ionenradius zu verwenden. Denn es scheint, als ob die Ionen dieser Seltenerdmetalle bevorzugt in die keramische Phase des Cermet-Bauteils eindiffundieren. Insbesondere genügt es, ein einziges Seltenerdmetall-Oxid zu verwenden, dessen Ionenradius kleiner gleich dem Ionenradius desjenigen Seltenerdmetallions ist, das in der Füllung den kleinsten Ionenradius aufweist. Empfehlenswert ist ein effektiver Ionenradius bis maximal etwa 0,091 nm. Vor allem das Scandium-Ion (Sc3+) ist geeignet, bei einer Koordinationszahl von 6. Diese Ausführungsform hat den Vorteil, daß sie unabhängig von der speziellen Wahl der Füllung ist und daher für mehrere Typen gemeinsam verwendet werden kann.It is particularly simple and effective to use predominantly or exclusively an oxide of a rare earth metal with the smallest possible ion radius as the rare earth metal oxide. Because it seems as if the ions of these rare earth metals preferentially diffuse into the ceramic phase of the cermet component. In particular, it is sufficient to use a single rare earth oxide whose ionic radius is less than or equal to the ionic radius of the rare earth metal ion which has the smallest ionic radius in the filling. An effective ion radius up to a maximum of about 0.091 nm is recommended. Above all, the scandium ion (Sc 3+ ) is suitable, with a coordination number of 6. This embodiment has the advantage that it is independent of the particular choice of filling and therefore for multiple types can be used together.

Die Anwendung dieses speziellen Cermet-Bauteils ist bei allen Metallhalogenidlampen mit keramischem Entladungsgefäß möglich, unabhängig davon, ob die Abdichtung mittels Schmelzkeramik oder durch Direkteinsinterung erfolgt.This special cermet component is used in all metal halide lamps possible with ceramic discharge vessel, regardless of whether the seal by means of melting ceramics or by direct sintering.

Die Herstellung des speziellen Cermets kann prinzipiell in an sich bekannter Weise durch Verarbeiten einer entsprechenden Pulvermischung erfolgen. Die grundsätzliche Eignung derartiger Materialien (insbesondere Yttrium-Aluminium-Granat) für den Lampenbau ist bereits bekannt ist, siehe US-A 5 698 948. Dort wird das Material jedoch für Entladungsgefäße eingesetzt. Dagegen spielt das Erfordernis der Transluzenz bei Durchführungen keine Rolle.In principle, the production of the special cermet can be carried out in a manner known per se by processing an appropriate powder mixture. The basic Suitability of such materials (especially yttrium aluminum garnet) for the lamp construction is already known, see US-A 5 698 948. There the material however used for discharge vessels. The requirement of Translucency does not matter in the implementation.

Vorteilhaft besteht das Mittel zum Abdichten (meist ein Stopfen) aus Keramik oder Cermet (beispielsweise geeignet dotiertem Aluminiumoxid), wobei das keramische Basismaterial des Cermet-Bauteils einem keramischen Hauptbestandteil des Mittels zum Abdichten entspricht, hier also Aluminiumoxid. Diese Anordnung hat den Vorteil, daß die thermische Ausdehnungskoeffizienten beider Teile einander ähneln, so daß eine Direkteinsinterung des Cermet-Bauteils im Stopfen besonders gut gelingt.The means for sealing (usually a stopper) advantageously consists of ceramic or Cermet (for example, suitably doped aluminum oxide), the ceramic Base material of the cermet component is a ceramic main component of the agent corresponds to sealing, here aluminum oxide. This arrangement has the advantage that the thermal expansion coefficients of both parts are similar, so that a direct sintering of the cermet component in the stopper is particularly successful.

Figurencharacters

Im folgenden soll die Erfindung anhand mehrerer Ausführungsbeispiele näher erläutert werden. Es zeigen:

Figur 1
eine Metallhalogenidlampe, im Schnitt
Figur 2
den Anteil verschiedener Seltenerdmetalle im Cermetstift
Figur 3
das Entladungsgefäß einer Metallhalogenidlampe, im Schnitt
Figur 4
ein weiteres Ausführungsbeispiel eines Cermetstifts
Figur 5
noch ein weiteres Ausführungsbeispiel eines Cermetstifts
Figur 6
ein weiteres Ausführungsbeispiel eines Entladungsgefäßes im Schnitt
The invention will be explained in more detail below with the aid of several exemplary embodiments. Show it:
Figure 1
a metal halide lamp, in section
Figure 2
the proportion of various rare earth metals in the cermet stick
Figure 3
the discharge vessel of a metal halide lamp, in section
Figure 4
another embodiment of a cermet stick
Figure 5
yet another embodiment of a cermet stick
Figure 6
a further embodiment of a discharge vessel in section

Beschreibung der ZeichnungenDescription of the drawings

In Figur 1 ist schematisch eine Metallhalogenidlampe mit einer Leistung von 250 W dargestellt. Sie besteht aus einem eine Lampenachse definierenden zylindrischen Außenkolben 1 aus Quarzglas, der zweiseitig gequetscht (2) und gesockelt (3) ist. Das axial angeordnete Entladungsgefäß 4 aus Al2O3-Keramik ist in der Mitte 5 ausgebaucht und besitzt zwei zylindrische Enden 6a und 6b. Es ist mittels zweier Stromzuführungen 7, die mit den Sockelteilen 3 über Folien 8 verbunden sind, im Außenkolben 1 gehaltert. Die Stromzuführungen 7 sind mit Durchführungen 9, 10 verschweißt, die jeweils in einem Endstopfen 11 am Ende des Entladungsgefäßes eingepaßt sind. A metal halide lamp with an output of 250 W is shown schematically in FIG. It consists of a cylindrical outer bulb 1 made of quartz glass which defines a lamp axis and is squeezed (2) and base (3) on two sides. The axially arranged discharge vessel 4 made of Al 2 O 3 ceramic is bulged in the middle 5 and has two cylindrical ends 6a and 6b. It is held in the outer bulb 1 by means of two power leads 7, which are connected to the base parts 3 via foils 8. The power supply lines 7 are welded to bushings 9, 10 which are each fitted in an end plug 11 at the end of the discharge vessel.

Die Durchführungen 9, 10 sind Cermet-Stifte mit einem Durchmesser von ca. 1 mm, die aus einem elektrisch leitfähigen Cermet bestehen.The bushings 9, 10 are cermet pins with a diameter of approx. 1 mm, which consist of an electrically conductive cermet.

Beide Durchführungen 9, 10 erstrecken sich über die gesamte Länge des Stopfens 11 und haltern entladungsseitig Elektroden 14, bestehend aus einem Elektrodenschaft 15 aus Wolfram und einer am entladungsseitigen Ende aufgeschobenen Wendel 16. Die Durchführung 9, 10 ist jeweils mit dem Elektrodenschaft 15 sowie mit der äußeren Stromzuführung 7 stumpf verschweißt.Both bushings 9, 10 extend over the entire length of the plug 11 and hold electrodes 14 on the discharge side, consisting of an electrode shaft 15 made of tungsten and one pushed on at the discharge end Spiral 16. The bushing 9, 10 is in each case with the electrode shaft 15 and butt welded to the external power supply 7.

Die Füllung des Entladungsgefäßes besteht neben einem inerten Zündgas, z.B. Argon, und evtl. Quecksilber aus Zusätzen an Halogeniden von Metallen, davon mindestens einem Seltenerdmetall.The discharge vessel is filled with an inert ignition gas, e.g. Argon, and possibly mercury from additions to metal halides, thereof at least one rare earth metal.

Als Mittel zum Abdichten werden Endstopfen 11 verwendet, die beispielsweise im wesentlichen aus Al2O3 bestehen. Möglich ist auch die Verwendung eines nichtleitenden Cermets mit der Hauptkomponente Al2O3, wobei als metallische Komponente Wolfram mit einem Anteil von ca. 30 Gew.-% enthalten ist (oder auch Molybdän mit entsprechend höherem Anteil).End plugs 11 are used as means for sealing, which essentially consist of Al 2 O 3 , for example. It is also possible to use a non-conductive cermet with the main component Al 2 O 3 , with tungsten being present as a metallic component in a proportion of approximately 30% by weight (or molybdenum with a correspondingly higher proportion).

Die Durchführung 9, 10 ist jeweils im Stopfen 11 direkt eingesintert. In ähnlicher Weise ist auch der Stopfen 11 jeweils in das zylindrische Ende 6 des Entladungsgefäßes direkt (also ohne Glaslot bzw. Schmelzkeramik) eingesintert.The bushing 9, 10 is sintered directly into the plug 11. More like that The plug 11 is also in each case in the cylindrical end 6 of the discharge vessel sintered directly (i.e. without glass solder or melting ceramic).

Am zweiten Ende 6b ist außerdem im Stopfen 11 eine achsparallele Bohrung 12 vorgesehen, die zum Evakuieren und Füllen des Entladungsgefäßes in an sich bekannter Weise dient. Diese Bohrung 12 wird nach dem Füllen mittels eines Stiftes 13 oder mittels Schmelzkeramik verschlossen. Der Stift besteht üblicherweise aus Keramik oder Cermet.At the second end 6b there is also an axially parallel bore 12 in the plug 11 provided for evacuating and filling the discharge vessel in a known manner Way serves. This bore 12 is made after filling by means of a pin 13 or closed by means of melting ceramic. The pen usually consists of Ceramics or cermet.

Beispielsweise eignet sich als Durchführung 9, 10 ein Cermet-Stift, der neben der keramischen Phase mit dem Basismaterial Aluminiumoxid mindestens 44 Vol.-% Metall (bevorzugt zwischen 45 und 75 Vol.-%) enthält und elektrisch leitend ist. Insbesondere eignet sich 70 bis 90 Gew.-% Wolfram oder 55 bis 80 Gew.-% Molybdän (oder eine hinsichtlich des Volumens äquivalente Menge an Rhenium). Die keramische Phase besteht vollständig aus Granat (s.u.).For example, a cermet pen is suitable as bushing 9, 10, which in addition to ceramic phase with the base material aluminum oxide at least 44 vol .-% Contains metal (preferably between 45 and 75 vol .-%) and is electrically conductive. In particular 70 to 90% by weight of tungsten or 55 to 80% by weight of molybdenum is suitable (or an amount of rhenium equivalent in volume). The ceramic Phase consists entirely of garnet (see below).

Für den Endstopfen eignet sich als Material ein Cermet, das einen geringeren Anteil an Metall als die Durchführung (bevorzugt etwa die Hälfte des Anteils bei der Durchführung) enthält. Wesentliche Eigenschaft des Stopfens ist dabei, daß sein thermischer Ausdehnungskoeffizient zwischen dem der Durchführung und dem des Entladungsgefäßes liegt. Der Metallanteil des Stopfens kann aber auch bei Null liegen.A cermet with a lower percentage is suitable as the material for the end plug of metal as the feedthrough (preferably about half the proportion in the Implementation) contains. An essential property of the plug is that coefficient of thermal expansion between that of implementation and that of Discharge vessel is. The metal content of the stopper can also be zero.

Das Anschweißen der Elektrode an der Stirnfläche der Durchführung erfolgt vor dem Einsintern der Durchführung in den Stopfen. Der schweißbare Cermet-Stift ist bereits vor dem endgültigen Einsintern weitgehend vorgesintert. Mittels der Metallhalogenide in der Füllung wird eine neutralweiße Lichtfarbe (NDL) erzielt (Farbtemperatur ca. 4300 K) unter Mitwirkung folgender Bestandteile (in Gew.-%):
9,0 % TIJ; 32,5% NaJ; je 19,5% der Seltenerdmetall-Jodide Dy2J3, Ho2J3 und Tm2J3.
The electrode is welded to the end face of the bushing before the bushing is sintered into the stopper. The weldable cermet pin is largely pre-sintered before it is finally sintered. Using the metal halides in the filling, a neutral white light color (HPS) is achieved (color temperature approx. 4300 K) with the participation of the following components (in% by weight):
9.0% TIJ; 32.5% NaJ; 19.5% each of the rare earth iodides Dy 2 J 3 , Ho 2 J 3 and Tm 2 J 3 .

Der Anteil der Seltenerdmetall-Ionen (in Gew.-%) betrug dementsprechend in der Füllung am Anfang:
Dy3+ 5,8 % und Ho3+ 5,9 % und Tm3+ 6,0 %.
The proportion of rare earth metal ions (in% by weight) was accordingly in the filling at the beginning:
Dy 3+ 5.8% and Ho 3+ 5.9% and Tm 3+ 6.0%.

Es wurde ein Vergleich zwischen baugleichen Lampen mit unterschiedlich zusammengesetzten Cermetstiften durchgeführt, wobei in der Kontrollgruppe ein konventioneller Cermetstift verwendet wurde (nur Aluminiumoxid als keramische Phase). Die erfindungsgemäßen Cermetstifte verwendeten zusätzlich Seltenerdmetall-Oxide.A comparison was made between identical lamps with different compositions Cermet sticks performed, with a conventional one in the control group Cermet stick was used (only alumina as the ceramic phase). The cermet sticks according to the invention additionally used rare earth oxides.

Durch Reaktion mit der Füllung entstand während des Betriebs im elektrodennahen Teil des konventionellen Cermetstifts eine stabile Struktur entsprechend der chemischen Verbindung mit 62,5 Mol.-% (30,9 Gew.-%) Aluminiumoxid, 9,6 Mol.-% (17,4 Gew.-%) Dysprosiumoxid, 11,5 Mol.-% (21,1 Gew.-%) Holmiumoxid und 16,4 Mol.-% (30,6 Gew.-%) Thuliumoxid, was einem Granat der chemischen Formel 0,77 Dy2O3 • 0,92 Ho2O3 • 1,31 Tm2O3 • 5 Al2O3 entspricht. Insgesamt wurde der Füllung 22% des darin enthaltenen Dy, 27 % des Ho und 38% des Tm entzogen und im Cermet eingelagert.By reaction with the filling, a stable structure corresponding to the chemical compound with 62.5 mol% (30.9% by weight) of aluminum oxide, 9.6 mol% (17) was formed during operation in the part of the conventional cermet stick near the electrodes , 4 wt%) dysprosium oxide, 11.5 mol% (21.1 wt%) holmium oxide and 16.4 mol% (30.6 wt%) thulium oxide, which is a garnet of chemical Formula 0.77 Dy 2 O 3 • 0.92 Ho 2 O 3 • 1.31 Tm 2 O 3 • 5 Al 2 O 3 . A total of 22% of the Dy contained therein, 27% of the Ho and 38% of the Tm was removed and stored in the cermet.

In der umgewandelten Keramik des konventionellen Cermet-Bauteils reicherte sich das Seltenerdmetall-Ion mit dem kleinsten effektiven Ionenradius, nämlich Tm (etwa 0,088 nm Ionenradius, siehe hierzu Fig. 2), deutlich stärker an als die beiden anderen:
Dy3+ 15,2 Gew.-% ; Ho3+ 18,4 Gew.-% und Tm3+ 26,8 Gew.-%.
In the converted ceramic of the conventional cermet component, the rare earth ion with the smallest effective ion radius, namely Tm (about 0.088 nm ion radius, see Fig. 2), accumulated significantly more than the other two:
Dy 3+ 15.2% by weight; Ho 3+ 18.4 wt% and Tm 3+ 26.8 wt%.

Während also in der Füllung die drei Seltenerdmetalle in annähernd gleicher Konzentration enthalten sind, ist im Cermet-Bauteil - offenbar wegen der unterschiedlichen Ionenradien - das Ho um 22% und das Tm um 77% stärker eindiffundiert als das Dy. Es ist außerordentlich erstaunlich, daß derart geringe Unterschiede im lonenradius derart drastische Konsequenzen haben können.So while in the filling the three rare earth metals in approximately the same concentration is contained in the cermet component - apparently because of the different Ion radii - the Ho diffuses in by 22% and the Tm by 77% more than the dy. It is extremely surprising that such small differences in the ionic radius can have such drastic consequences.

In einem ersten Ausführungsbeispiel der Erfindung wurde ein Cermet-Bauteil verwendet, das von vornherein als keramische Phase etwa die sich natürliche einstellende Gleichgewichtsverteilung verwendet und somit diesen Diffusionsprozeß vorwegnimmt:In a first exemplary embodiment of the invention, a cermet component was used, that from the outset as the ceramic phase, for example the natural one Equilibrium distribution used and thus anticipates this diffusion process:

31 Gew.-% Aluminiumoxid, 15 Gew.-% Dysprosiumoxid, 20 Gew.-% Holmiumoxid und 34 Gew.-% Thuliumoxid.31% by weight of aluminum oxide, 15% by weight of dysprosium oxide, 20% by weight of holmium oxide and 34 wt% thulium oxide.

In einem zweiten Ausführungsbeispiel wurde für dieses Cermet-Bauteil als keramische Phase ein regulärer Granat unter alleiniger Verwendung von Tm2O3 als Seltenerdmetall-Oxid mit Aluminiumoxid als Basismaterial eingesetzt.In a second exemplary embodiment, a regular garnet was used as the ceramic phase for this cermet component, using only Tm 2 O 3 as the rare earth oxide with aluminum oxide as the base material.

Das Ergebnis war annähernd gleichwertig. Die effektiven Lebensdauern beider Ausführungsbeispiele konnten gegenüber der Kontrollgruppe um mehr als einen Faktor 1,5 gesteigert werden. Erwartungsgemäß schnitt dabei das erste Ausführungsbeispiel um etwa 10 % besser ab als das zweite (da noch geringe Mengen der anderen Seltenerdmetall-Ionen in das Cermet eindiffundierten), doch ist diese relativ geringfügige Verbesserung nicht immer durch die deutlich höheren Kosten gerechtfertigt.The result was almost equivalent. The effective lifetimes of both Exemplary embodiments could be compared to the control group by more than one Factor of 1.5 can be increased. As expected, the first embodiment cut about 10% better than the second (since small amounts of the other rare earth metal ions diffused into the cermet), but this is relative slight improvement is not always justified by the significantly higher costs.

In einem dritten Ausführungsbeispiel wird als Seltenerdmetall-Oxid Sc2O3 (oder auch Yb2O3) verwendet. Beide Ionen besitzen einen kleineren Ionenradius (0,075 bzw. 0,087 nm) als die in der Füllung verwendeten Seltenerdmetall-Ionen. Die damit erzielte Lebendsdauer entspricht ungefähr der des zweiten Ausführungsbeispiels.In a third exemplary embodiment, Sc 2 O 3 (or also Yb 2 O 3 ) is used as the rare earth metal oxide. Both ions have a smaller ion radius (0.075 or 0.087 nm) than the rare earth metal ions used in the filling. The life span achieved in this way corresponds approximately to that of the second exemplary embodiment.

In einer zweiten Ausführungsform (Fig. 3) ist an den Enden des annähernd kreiszylindrischen Entladungsgefäßes 25 jeweils ein nicht-leitender Stopfen 26 direkt eingesintert. Die Durchführung ist ein elektrisch leitender Cermet-Stift 9, 10 mit einem Metallanteil von 50 Vol.-%. Der Rest ist eine keramische Phase. Der Stopfen 26 aus Aluminiumoxid besteht aus zwei konzentrischen Teilen, einem äußeren ringförmigen Stopfenteil 21 und einem inneren, etwa doppelt so langen Kapillarrohr 20. Trotzdem ist das Kapillarrohr im Vergleich zu bekannten Kapillarrohr-Techniken etwa 50 % . kürzer. Die im Vergleich zum Stopfenteil 21 große Baulänge des Kapillarrohrs verbessert das Abdichtverhalten. Der Cermet-Stift 9 ist im Kapillarrohr 20 vertieft eingesetzt und dort direkt eingesintert. Die Füllbohrung 22 ist im äußeren Stopfenteil 21 untergebracht.In a second embodiment (Fig. 3) is at the ends of the approximately circular cylindrical Discharge vessel 25 each sintered a non-conductive plug 26 directly. The implementation is an electrically conductive cermet pin 9, 10 with a Metal content of 50% by volume. The rest is a ceramic phase. The plug 26 out Aluminum oxide consists of two concentric parts, an outer annular one Plug part 21 and an inner, about twice as long capillary tube 20. Nevertheless the capillary tube is about 50% compared to known capillary tube techniques , shorter. The large length of the capillary tube compared to the plug part 21 improved the sealing behavior. The cermet pin 9 is recessed in the capillary tube 20 and sintered there directly. The filling bore 22 is in the outer plug part 21 accommodated.

Da der Cermetstift vertieft eingesetzt ist, wird nur an seiner Stirnfläche 19 über eine axiale Länge von etwa 1 mm eine Eu2O3-Perowskitstruktur als keramische Phase verwendet, die in einer anschließenden Übergangszone allmählich in die bekannte Struktur mit reiner Aluminiumoxid-Phase übergeht, die am Ende des Stiftes Verwendung findet.Since the cermet pin is used in a recessed manner, an Eu 2 O 3 perovskite structure is used as the ceramic phase only on its end face 19 over an axial length of approximately 1 mm, which gradually changes into the known structure with a pure aluminum oxide phase in a subsequent transition zone, which is used at the end of the pen.

Figur 4 zeigt einen Cermetstift 27, der aus zwei Teilen zusammengesetzt ist. Der vordere Frontteil 28 hat als keramische Phase eine Granatstruktur mit Aluminiumoxid als Basismaterial und Er2O3 als Seltenerdmetall-Oxid. Er besitzt eine axiale Nase 29, mit der er in einer kreiszylindrische Bohrung eines dahinter angeordneten Verlängerungsteils 30 eingepaßt ist. Beide Teile sind durch Direkteinsinterung miteinander verbunden.Figure 4 shows a cermet pin 27, which is composed of two parts. The front front part 28 has a garnet structure as a ceramic phase with aluminum oxide as the base material and Er 2 O 3 as the rare earth oxide. It has an axial nose 29 with which it is fitted into a circular cylindrical bore of an extension part 30 arranged behind it. Both parts are connected by direct sintering.

Alternativ können beide Teile des Cermetstifts 31, deren Cermets schweißbar sind, indem der Anteil der metallischen Phase (Mo) bei jeweils ca. 50 Vol.-% liegt, miteinander stumpf verschweißt sein, wie in Figur 5 dargestellt. Das Frontteil 32 und das Verlängerungsteil 33 sind dabei etwa gleich lang. Beim Frontteil wird YAG (Yttrium-Aluminium-Granat, 3 Y2O3 • 5 Al2O3) für eine 500 µm breite Zone an der Stirnseite und den seitlichen Mantelflächen als keramische Phase verwendet. Es hat sich herausgestellt, daß ein effektiver Schutz gegen das Eindiffundieren der Seltenerdmetalle aus der Füllung in das Cermet eine Zone von mindestens 200 µm Dicke erfordert. Gute Ergebnisse werden mit einer Dicke zwischen 200 und 700 µm erzielt, vorausgesetzt.Alternatively, both parts of the cermet pin 31, the cermets of which can be welded by the proportion of the metallic phase (Mo) being approximately 50% by volume, can be butt-welded to one another, as shown in FIG. 5. The front part 32 and the extension part 33 are approximately the same length. For the front part, YAG (yttrium aluminum garnet, 3 Y 2 O 3 • 5 Al 2 O 3 ) is used as a ceramic phase for a 500 µm wide zone on the front and the lateral surface. It has been found that effective protection against the diffusion of the rare earth metals from the filling into the cermet requires a zone of at least 200 µm in thickness. Good results are achieved with a thickness between 200 and 700 µm, provided that.

In Figur 6 ist ein weiteres Ausführungsbeispiel gezeigt, bei der das Ende des zylindrischen keramischen Entladungsgefäßes 40 (aus Aluminiumoxid) durch eine keramische Endplatte 41 und einen rohrförmigen Stopfen 42 verschlossen ist. Eine zweiteilige Durchführung 43 ist mittels Glaslot 44 im Stopfen abgedichtet. Die Durchführung 43 besteht aus einem entladungsseitigen Cermetstift 45 und einem entladungsabgewandten Niobstift 46. Am Cermetstift ist die Elektrode 47 befestigt. Die Oberfläche des Cermetstifts ist von einer 300 µm dicken Schicht 48 aus YAG abgedeckt. Die leitende Phase (60 Vol.-%) des Cermetstifts besteht aus MoSi2, die keramische Phase (Rest) besteht aus 50 Mol.-% Al2O3 und 50 Mol.-% einer Mischung aus YAG und Eu2O3-Perowskit. Die Füllung enthält als Seltenerdmetalljodide DyJ3 und CeJ3.FIG. 6 shows a further exemplary embodiment in which the end of the cylindrical ceramic discharge vessel 40 (made of aluminum oxide) is closed by a ceramic end plate 41 and a tubular plug 42. A two-part bushing 43 is sealed by means of glass solder 44 in the stopper. The bushing 43 consists of a cermet pin 45 on the discharge side and a niobium pin 46 facing away from the discharge. The electrode 47 is fastened to the cermet pin. The surface of the cermet stick is covered by a 300 μm thick layer 48 of YAG. The conductive phase (60 vol.%) Of the cermet stick consists of MoSi 2 , the ceramic phase (rest) consists of 50 mol.% Al 2 O 3 and 50 mol.% Of a mixture of YAG and Eu 2 O 3 - perovskite. The filling contains DyJ 3 and CeJ 3 as rare earth metal iodides.

Claims (13)

  1. Metal halide lamp with a ceramic discharge vessel (4), the discharge vessel having two ends (6a, 6b) which are each closed off by sealing means, and in each case one electrically conductive lead-through (9, 10; 30) being guided through these means in a vacuum-tight manner, to which lead-through an electrode (14) is attached, which electrode projects into the interior of the discharge vessel, at least a front part (45) of the lead-through, which part faces toward the discharge, being designed as a halide-resistant component made from electrically conductive cermet which is composed of a first electrically conductive phase and a second ceramic phase, which comprises a ceramic base material, and the fill comprising at least one rare-earth metal including the metals yttrium and scandium, characterized in that at least at a surface (28; 32) of the cermet component which is accessible to the fill, at least some of the ceramic phase comprises the combination of the ceramic base material with one or more rare-earth metal oxides.
  2. Metal halide lamp according to Claim 1, characterized in that the component made from cermet is in the form of a cermet pin (9, 10).
  3. Metal halide lamp according to Claim 1, characterized in that the cermet contains, as the electrically conductive phase, molybdenum or tungsten or rhenium or their alloys or MoSi2.
  4. Metal halide lamp according to Claim 1, characterized in that in the entire component, part of the ceramic phase comprises the combination of the ceramic base material and one or more rare-earth metal oxides.
  5. Metal halide lamp according to Claim 1, characterized in that the entire ceramic phase consists of the combination of the ceramic base material and one or more rare-earth metal oxides.
  6. Metal halide lamp according to Claim 1,
    characterized in that the ceramic base material is aluminium oxide.
  7. Metal halide lamp according to Claim 1, characterized in that the rare-earth metal oxides comprise the oxides of some or all of the rare-earth metals which are contained in the fill.
  8. Metal halide lamp according to Claim 1, characterized in that the rare-earth metal oxides comprise the oxides of one or more rare-earth metals which are not contained in the fill, in particular Y2O3.
  9. Metal halide lamp according to Claim 1, characterized in that the combination of the ceramic base material and the one or more rare-earth metal oxides corresponds to a garnet or perovskite or a mixture of the two.
  10. Metal halide lamp according to Claim 1, characterized in that the rare-earth metal oxides used are predominantly or exclusively the oxides of rare-earth metals with the smallest possible ionic radius, in particular with an ionic radius which is less than or equal to the ionic radius of rare-earth metals contained in the fill.
  11. Metal halide lamp according to Claim 1, characterized in that the fill contains the rare-earth metal as a halide.
  12. Metal halide lamp according to Claim 1, characterized in that the sealing means (20) comprises ceramic or cermet, the ceramic base material of the cermet component (9) corresponding to a principal ceramic constituent of the sealing means.
  13. Metal halide lamp according to Claim 1, characterized in that the surface is situated on the front side and, if appropriate, on the lateral surface of the cermet component.
EP00100687A 1999-02-26 2000-01-14 Metal halide lamp with ceramic discharge vessel Expired - Lifetime EP1032022B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19908688 1999-02-26
DE19908688A DE19908688A1 (en) 1999-02-26 1999-02-26 Metal halide lamp with ceramic discharge tube

Publications (2)

Publication Number Publication Date
EP1032022A1 EP1032022A1 (en) 2000-08-30
EP1032022B1 true EP1032022B1 (en) 2004-09-15

Family

ID=7899182

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00100687A Expired - Lifetime EP1032022B1 (en) 1999-02-26 2000-01-14 Metal halide lamp with ceramic discharge vessel

Country Status (7)

Country Link
US (1) US6404130B1 (en)
EP (1) EP1032022B1 (en)
JP (1) JP4567134B2 (en)
AT (1) ATE276584T1 (en)
CA (1) CA2298270A1 (en)
DE (2) DE19908688A1 (en)
HU (1) HUP0000904A3 (en)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6805603B2 (en) * 2001-08-09 2004-10-19 Matsushita Electric Industrial Co., Ltd. Electrode, manufacturing method thereof, and metal vapor discharge lamp
US7525252B2 (en) * 2002-12-27 2009-04-28 General Electric Company Sealing tube material for high pressure short-arc discharge lamps
US20060125402A1 (en) * 2003-01-27 2006-06-15 Meeuwsen Johannes F Method for filling a lamp with gas and a lamp filled with gas
US6774547B1 (en) 2003-06-26 2004-08-10 Osram Sylvania Inc. Discharge lamp having a fluted electrical feed-through
DE102004015467B4 (en) 2004-03-26 2007-12-27 W.C. Heraeus Gmbh Electrode system with a current feed through a ceramic component
WO2005109471A2 (en) * 2004-05-10 2005-11-17 Koninklijke Philips Electronics N.V. High-pressure discharge lamp with a closing member comprising a cermet
US7329979B2 (en) * 2004-07-15 2008-02-12 General Electric Company Electrically conductive cermet and devices made thereof
US7615929B2 (en) * 2005-06-30 2009-11-10 General Electric Company Ceramic lamps and methods of making same
WO2008089662A1 (en) * 2007-01-19 2008-07-31 Cnlight Co., Ltd. Electrode system for ceramic metal halide lamp
DE102007046899B3 (en) * 2007-09-28 2009-02-12 W.C. Heraeus Gmbh Halogen metal vapor lamp comprises a ceramic housing and a current feed-through arranged in the ceramic housing
DE102007055399A1 (en) 2007-11-20 2009-05-28 Osram Gesellschaft mit beschränkter Haftung Metal halide high pressure discharge lamp comprises ceramic discharge vessel with end, where electrode system is provided at end in sealing system
US8134290B2 (en) * 2009-04-30 2012-03-13 Scientific Instrument Services, Inc. Emission filaments made from a rhenium alloy and method of manufacturing thereof

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1571084A (en) * 1975-12-09 1980-07-09 Thorn Electrical Ind Ltd Electric lamps and components and materials therefor
NZ182774A (en) * 1975-12-09 1979-06-19 Thorn Electrical Ind Ltd Electrically conducting cermet
CA1082909A (en) * 1976-03-09 1980-08-05 Thorn Electrical Industries Limited Electric lamps and components and materials therefor
NL183092C (en) * 1976-08-05 1988-07-18 Philips Nv GAS DISCHARGE LAMP.
DE3063533D1 (en) * 1979-11-12 1983-07-07 Emi Plc Thorn An electrically conducting cermet, its production and use
DE3174149D1 (en) * 1980-12-20 1986-04-24 Emi Plc Thorn Discharge lamp arc tubes
NL8101177A (en) * 1981-03-11 1982-10-01 Philips Nv COMPOSITE BODY.
US5424609A (en) * 1992-09-08 1995-06-13 U.S. Philips Corporation High-pressure discharge lamp
EP0587238B1 (en) * 1992-09-08 2000-07-19 Koninklijke Philips Electronics N.V. High-pressure discharge lamp

Also Published As

Publication number Publication date
HUP0000904A3 (en) 2002-11-28
US6404130B1 (en) 2002-06-11
HU0000904D0 (en) 2000-04-28
EP1032022A1 (en) 2000-08-30
JP2000251842A (en) 2000-09-14
CA2298270A1 (en) 2000-08-26
HUP0000904A2 (en) 2000-09-28
DE19908688A1 (en) 2000-08-31
JP4567134B2 (en) 2010-10-20
ATE276584T1 (en) 2004-10-15
DE50007716D1 (en) 2004-10-21

Similar Documents

Publication Publication Date Title
EP0371315B1 (en) Discharge vessel for a high-pressure discharge lamp, and method for producing same
EP0887839B1 (en) Metal halide lamp with ceramic discharge vessel
EP0834905B1 (en) Low power high pressure sodium lamp
DE69817140T2 (en) MERCURY-FREE METAL HALOGEN LAMP
EP0652586B1 (en) Metal-halide discharge lamp with a ceramic discharge tube and method of making the same
DE10291427B4 (en) Metal halide lamp for a motor vehicle headlight
EP1032022B1 (en) Metal halide lamp with ceramic discharge vessel
EP0602529B1 (en) High-pressure discharge lamp having a ceramic discharge vessel
DE2161173B2 (en) Oxide electrode for high-power electric gas discharge lamps
DE10243867A1 (en) Mercury-free arc tube for discharge lamp unit
EP2020018B1 (en) High-pressure discharge lamp
EP0335202B1 (en) High-pressure lamp, especially a high-pressure sodium vapour lamp
EP1011126A2 (en) Metal halogen lamp
DE69731374T2 (en) LOW PRESSURE DISCHARGE LAMP
DE2641880C2 (en)
DE69824681T2 (en) High-pressure discharge lamp
DE1911985C3 (en) High pressure arc discharge lamp
DE69921901T2 (en) Cermet and ceramic discharge lamp
DE102006052715B4 (en) Process for producing a mercury-free arc tube, each having a single crystal at the electrode tips
EP1481417A1 (en) Mercury short arched lamp with a cathode containing lanthanum oxide
DE69824824T2 (en) GASKET OF LAMP PISTON
WO1995010120A1 (en) Metal halogenide discharge lamp
EP1351278B1 (en) Metal halide lamp with ceramic discharge vessel
DE202010018034U9 (en) High pressure discharge lamp
DE2619866C3 (en) Gas discharge tubes, in particular surge arresters

Legal Events

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

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17P Request for examination filed

Effective date: 20000918

AKX Designation fees paid

Free format text: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

17Q First examination report despatched

Effective date: 20030509

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

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

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20040915

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040915

Ref country code: FR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040915

Ref country code: GB

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040915

Ref country code: IE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040915

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: GERMAN

REF Corresponds to:

Ref document number: 50007716

Country of ref document: DE

Date of ref document: 20041021

Kind code of ref document: P

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

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20041215

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20041215

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20041215

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

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20041226

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

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20050114

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050114

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

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050131

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050131

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050131

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050131

GBV Gb: ep patent (uk) treated as always having been void in accordance with gb section 77(7)/1977 [no translation filed]

Effective date: 20040915

REG Reference to a national code

Ref country code: IE

Ref legal event code: FD4D

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

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

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

26N No opposition filed

Effective date: 20050616

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

EN Fr: translation not filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050215

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20090129

Year of fee payment: 10

REG Reference to a national code

Ref country code: NL

Ref legal event code: V1

Effective date: 20100801

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

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100801

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20110321

Year of fee payment: 12

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20110218

Year of fee payment: 12

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 50007716

Country of ref document: DE

Owner name: OSRAM AG, DE

Free format text: FORMER OWNER: OSRAM GESELLSCHAFT MIT BESCHRAENKTER HAFTUNG, 81543 MUENCHEN, DE

Effective date: 20111128

BERE Be: lapsed

Owner name: *PATENT-TREUHAND-G.- FUR ELEKTRISCHE GLUHLAMPEN M.

Effective date: 20120131

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

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120801

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 50007716

Country of ref document: DE

Effective date: 20120801

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

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20120131