EP0882307A1 - Electrode de frittage - Google Patents

Electrode de frittage

Info

Publication number
EP0882307A1
EP0882307A1 EP97951066A EP97951066A EP0882307A1 EP 0882307 A1 EP0882307 A1 EP 0882307A1 EP 97951066 A EP97951066 A EP 97951066A EP 97951066 A EP97951066 A EP 97951066A EP 0882307 A1 EP0882307 A1 EP 0882307A1
Authority
EP
European Patent Office
Prior art keywords
powder
grain size
metal
sintered
sintered electrode
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.)
Granted
Application number
EP97951066A
Other languages
German (de)
English (en)
Other versions
EP0882307B1 (fr
Inventor
Dietrich Fromm
Bernhard Altmann
Wolfram Graser
Peter Schade
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 EP0882307A1 publication Critical patent/EP0882307A1/fr
Application granted granted Critical
Publication of EP0882307B1 publication Critical patent/EP0882307B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/04—Electrodes; Screens; Shields
    • H01J61/06—Main electrodes
    • H01J61/073—Main electrodes for high-pressure discharge lamps
    • H01J61/0735—Main electrodes for high-pressure discharge lamps characterised by the material of the electrode
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12014—All metal or with adjacent metals having metal particles
    • Y10T428/12028—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
    • Y10T428/12042—Porous component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12014—All metal or with adjacent metals having metal particles
    • Y10T428/12028—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
    • Y10T428/12063—Nonparticulate metal component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12014—All metal or with adjacent metals having metal particles
    • Y10T428/12153—Interconnected void structure [e.g., permeable, etc.]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12639—Adjacent, identical composition, components
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12639—Adjacent, identical composition, components
    • Y10T428/12646—Group VIII or IB metal-base
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
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    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12778—Alternative base metals from diverse categories
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
    • Y10T428/12819—Group VB metal-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
    • Y10T428/12826—Group VIB metal-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
    • Y10T428/12826—Group VIB metal-base component
    • Y10T428/12833—Alternative to or next to each other
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
    • Y10T428/12826—Group VIB metal-base component
    • Y10T428/1284—W-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12861—Group VIII or IB metal-base component
    • Y10T428/12875—Platinum group metal-base component

Definitions

  • the invention is based on a sintered electrode according to the preamble of claim 1. It is a sintered electrode for high-pressure discharge lamps such as, for example, metal halide lamps or sodium high-pressure discharge lamps.
  • a thermionically emitting cathode element for vacuum electron tubes is known, which is made of spherical particles with an average grain size below 1 ⁇ m. 5 to 90% of the total volume of the sintered electrode consists of unfilled pores that are open to the environment. The distances between neighboring particles (grains) are less than 1 ⁇ m.
  • a sintered electro which contains, in addition to tungsten, portions of emitter material such as oxides of aluminum, barium, calcium or thorium.
  • the sintered body sits on a solid core pin made of solid material.
  • a cathode which consists of a porous tungsten matrix, in the pores of which emitter material is incorporated. The pores are produced by filling the green body of the matrix with liquid copper, which is later removed again.
  • the disadvantage of this method is that the pores are irregular in shape and their properties are undefined. Manufacturing is complicated and time consuming.
  • DD-PS 292 764 discloses a cermet sintered body consisting of a mixture of tungsten and thorium oxide or alkaline earth oxide, in which the porosity of the sintered body is controlled by the defined use of a binder in the production.
  • the particle size of the cermet powder is 80 to 550 ⁇ m.
  • sintered electrodes have so far not been able to establish themselves widely. Rather, it was previously dependent on the use of spiral electrodes with a core pin made of thoriated tungsten or pin electrodes made of thoriated tungsten. So far, each has been produced from compact, solid material.
  • the sintered electrode for high-pressure discharge lamps according to the invention consists of a sintered body made of one of the refractory metals tungsten, tantalum, osmium, iridium, molybdenum or rhenium or an alloy of these metals.
  • a known oxidic doping (up to 5% by weight) can be added to the metal or alloy, for example an oxide of lanthanum or yttrium.
  • the sintered body is made of an essentially spherical powder of the metal or the alloy, the mean grain size of which is between 2 and 100 ⁇ m, the grain size distribution fluctuating by a maximum of 20% around the mean and between 10 and 40% by volume of the total volume the sintered electrode consists of pores open to the environment.
  • the pores can be unfilled or contain emitter additives.
  • Typical emitter additives are oxides of alkaline earth, for example barium, calcium, strontium and mixtures thereof. Also suitable are aluminates and oxides of hafnium or zirconium or of the rare earth metals (in particular Sc, Y, La, Ce, Nd, Gd, Dy and Yb).
  • the average grain size of the spherical powder is preferably between 5 and 70 ⁇ m.
  • the grain size distribution fluctuates by a maximum of 10% around the mean value.
  • the sintered body is fastened in a manner known per se to a core pin made of solid metal.
  • a particular advantage is that connection techniques such as soldering or welding are not used can.
  • the mechanical connection is only made by shrinking or sintering.
  • the material of the sintered body and of the core pin is preferably essentially the same, for example pure tungsten.
  • the sintered body can be unfilled or contain emitter additives (for example lanthanum oxide). Pure tungsten doped with potassium or a rhenium-tungsten alloy is also suitable for the core pin.
  • the electrode can do without thorium and is then radioactive.
  • the service life of the high-pressure discharge lamps equipped with them is extended, the rise in lamp lamp voltage is reduced and the maintenance of the luminous flux is significantly improved.
  • the blackening of the wall of the discharge vessel is reduced.
  • the operation of the lamps shows a reduction in the uneven arc and flicker.
  • the manufacture of the electrode is significantly simplified. The electrode coil can be saved compared to conventional electrodes.
  • a particularly advantageous method for producing a sintered body according to claim 1 consists of the following method steps:
  • the average grain size of the metal powder is between 2 and 100 ⁇ m; the grain size distribution fluctuates by a maximum of 20% (typically 10%) around the mean value; in particular, the spherical particles of the metal powder used for this are single-crystalline;
  • a typical value of the pressure used is 100 to 400 MPa;
  • the powder is preferably single crystal.
  • the powder can in particular be pressed around a core pin.
  • Process step c) can be carried out, for example, in the case of tungsten, preferably at temperatures of 2500 to 2800 K.
  • the melting temperature means that of the lowest melting component.
  • the pressing can advantageously be carried out without the addition of a binder. This saves an additional processing step and prevents possible contamination.
  • Another advantageous process is the metal injection molding process. This technique is described in more detail in parallel application 97P5568. It can also be used in a modified form for the present invention.
  • the sequence of the process can be briefly summarized as follows: A suitable metal powder is mixed with so much plastic (the so-called binder) that this starting material, which is in the form of granules, assumes the flow properties of the plastic and can be further processed analogously to plastic injection molding by placing it in an injection mold with the contour of the desired future component. Then to create a metallic to obtain the component, the green body is removed from the injection mold; the binder is then removed from the so-called green body by heat or by solvent. This process is called dewaxing. The component is then sintered into a component of very high density in accordance with classic powder metallurgy.
  • the essentially spherical metal powder is produced in a manner known per se, where rounded or almost exactly spherical particles can arise.
  • One example is the carbonyl process (New Types of Metal Powders, Ed. H. Hausner, Gordon and Breach Science Publishers, New York 1963, published in the series Metallurgical Society Conferences as Volume 23). Particularly good results are achieved with single-crystalline metal powder.
  • the spherical powder grains of homogeneous size develop equilibrium surfaces in the form of polyhedra during sintering. For example, there are [HO] or [111] faces. Surprisingly, it has been found that these polyhedron surfaces do not further unite, so that the porosity of this novel sintered body remains practically constant over the service life. It is a so-called sponge body with open porosity.
  • the starting material is spherical W powder with a diameter that is as uniform as possible, i.e. with a narrow distribution width of the grain size. This homogeneity of the powder ultimately results in great stability of the sintered body at high temperatures and leads to correspondingly stable conditions during the life of the lamp.
  • the powder can in particular be pressed directly around a Th ⁇ 2-free core pin. Sintering is then carried out at the relatively low temperature of around 2350 ( ⁇ 100) ° C. This low temperature, which corresponds approximately to 0.7 times the melting temperature of the tungsten, means considerable energy savings compared to the usual sintering temperatures of 2800-3000 ° C for compact tungsten material.
  • Additional emitter additives are not necessary in many applications, but can be introduced into the cavities or pores if necessary.
  • the residual porosity of the finished sintered sponge electrode can be set specifically via the ball size of the starting material. Ball sizes of 5 to 70 ⁇ m are preferably used for the sponge electrode. A residual porosity of about 15 to 30% by volume can thus be achieved.
  • the discharge begins on a large area.
  • the point-like approach known from conventional electrodes which there often leads to locally very high temperatures and migration of the focal spot, is avoided.
  • the temperature distribution over the entire sponge body is largely uniform.
  • a conventional electrode has a high temperature gradient. In particular, it has a temperature that is typically 500 K higher at the tip than in the rear part of the electrode.
  • the transition from the glow to the arc discharge takes place faster when using the sintered electrode than with the conventional solid electrode, since the heat dissipation from the tip of the electrode towards the pinch is greatly reduced due to the small contact area between the sintered grains of the sintered body .
  • the sponge electrode in particular in the vertical operating position, better heating of the area of the discharge vessel close to the pinch is achieved.
  • the cause is the larger surface of the electrode, which emits more light. Therefore, any reflective coating on the bulb ends can be made smaller or omitted entirely, which means that a higher luminous flux is achieved.
  • Figure 2 shows a metal halide lamp with a sintered electrode
  • the sintered electrode 1 shown in FIG. 1 for a 150 W lamp consists of a cylindrical sintered body 2, in the half of which is averted from the discharge, a solid core pin 5 made of tungsten is pressed axially.
  • the sintered body 2 consists of tungsten, which is made of spherical metal powder with an average grain size of 10 ⁇ m. The grain size distribution fluctuates around 10% around the mean. The residual porosity is approximately 15% by volume.
  • the diameter of the core pin is approximately 0.5 mm, the outer diameter of the sintered body is approximately 1.5 mm.
  • a metal halide lamp 9 with a power of 150 W. It consists of a quartz glass vessel 10 which contains a metal halide fill. External power supply lines 11 and molybdenum foils 12 are embedded in squeezes 13 at their two ends. The core pins 5 of the electrodes 1 are attached to the molybdenum foils 12. Last tere protrude into the discharge vessel 10. The two ends of the discharge vessel are each provided with a heat-reflecting coating 14 made of zirconium oxide.
  • the electrode consists of a sintered body which is rounded on the discharge side or tapers to a point.
  • the sintered body is made of tungsten
  • the pressed-in core pin is made of rhenium, rhenium-plated tungsten or molybdenum.
  • a particularly advantageous method for producing a sintered electrode according to the invention is based on the metal injection molding method known per se.
  • the principle in the parallel registration Akz is:
  • an essentially spherical, in particular single-crystalline, metal powder made of refractory metal such as tungsten, tantalum, molybdenum, osmium, iridium or rhenium or an alloy of these metals, the powder having the following properties: the average grain size of the metal powder is between 2 and 100 ⁇ m; the grain size distribution fluctuates by a maximum of 20% around the mean value; - Making a mixture (so-called "feedstock") from powder and binder (often referred to as "wax”) and possibly polymer;
  • the mixture is injected around a core pin in the injection mold and connected to it during sintering.
  • Such electrodes show a much better life behavior.
  • Studies on metal halide lamps with a power of 150 W show that the maintenance of the luminous flux after 1000 hours when using metal powders with a grain size of 5 or 20 ⁇ m amounts to 95% of the initial luminous flux.
  • a drop in the luminous flux to values between 83 and 90% can be observed in the prior art (conventional stick electrode made of doped tungsten material) after 1000 hours.

Landscapes

  • Discharge Lamp (AREA)
  • Powder Metallurgy (AREA)

Abstract

Cette électrode de frittage en un métal à haut point de fusion (par exemple le tungstène) est constituée d'une poudre métallique à grains sphériques d'une grosseur bien définie. La grosseur moyenne des grains est comprise entre 5 et 70 mu m. La distribution granulométrique oscille d'au maximum 20 % autour de la grosseur moyenne des grains.
EP97951066A 1996-12-18 1997-11-11 Electrode de frittage Expired - Lifetime EP0882307B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19652822A DE19652822A1 (de) 1996-12-18 1996-12-18 Sinterelektrode
DE19652822 1996-12-18
PCT/DE1997/002640 WO1998027575A1 (fr) 1996-12-18 1997-11-11 Electrode de frittage

Publications (2)

Publication Number Publication Date
EP0882307A1 true EP0882307A1 (fr) 1998-12-09
EP0882307B1 EP0882307B1 (fr) 2004-01-28

Family

ID=7815235

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97951066A Expired - Lifetime EP0882307B1 (fr) 1996-12-18 1997-11-11 Electrode de frittage

Country Status (9)

Country Link
US (1) US6218025B1 (fr)
EP (1) EP0882307B1 (fr)
JP (1) JP2000505939A (fr)
KR (1) KR19990082364A (fr)
CN (1) CN1123053C (fr)
CA (1) CA2246517C (fr)
DE (2) DE19652822A1 (fr)
HU (1) HU223302B1 (fr)
WO (1) WO1998027575A1 (fr)

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US6705914B2 (en) * 2000-04-18 2004-03-16 Matsushita Electric Industrial Co., Ltd. Method of forming spherical electrode surface for high intensity discharge lamp
DE10307716B4 (de) * 2002-03-12 2021-11-18 Taniobis Gmbh Ventilmetall-Pulver und Verfahren zu deren Herstellung
US7808180B2 (en) * 2003-05-26 2010-10-05 Koninklijke Philips Electronics N.V. Thorium-free electrode with improved color stability
WO2006048797A2 (fr) * 2004-11-02 2006-05-11 Koninklijke Philips Electronics N.V. Lampe a decharge, electrode et procede servant a fabriquer une partie electrode de lampe a decharge
US20090134799A1 (en) * 2004-11-02 2009-05-28 Koninklijke Philips Electronics, N.V. Discharge lamp, electrode, and method of manufacturing a component of a discharge lamp
JP2008527621A (ja) * 2005-01-03 2008-07-24 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ 照明アセンブリおよび放電ランプを作動させる方法
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JP4454527B2 (ja) 2005-03-31 2010-04-21 日本碍子株式会社 発光管及び高圧放電灯
JP4614908B2 (ja) * 2005-05-11 2011-01-19 日立粉末冶金株式会社 冷陰極蛍光ランプ用電極
DE102005035190A1 (de) * 2005-07-27 2007-02-01 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH Haltestab
JP2007095665A (ja) 2005-09-02 2007-04-12 Sony Corp ショートアーク型高圧放電電極、ショートアーク型高圧放電管、ショートアーク型高圧放電光源装置、及びそれらの各製造方法
US7652415B2 (en) * 2005-10-20 2010-01-26 General Electric Company Electrode materials for electric lamps and methods of manufacture thereof
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CN1211341A (zh) 1999-03-17
HUP9901361A2 (hu) 1999-08-30
HU223302B1 (hu) 2004-05-28
CA2246517A1 (fr) 1998-06-25
DE19652822A1 (de) 1998-06-25
US6218025B1 (en) 2001-04-17
HUP9901361A3 (en) 2000-04-28
JP2000505939A (ja) 2000-05-16
CN1123053C (zh) 2003-10-01
CA2246517C (fr) 2005-08-09
WO1998027575A1 (fr) 1998-06-25
KR19990082364A (ko) 1999-11-25
DE59711260D1 (de) 2004-03-04
EP0882307B1 (fr) 2004-01-28

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