US 7,514,871 B2
High-pressure gas-discharge lamp with improved temperature resistance
Robert Peter Scholl, Roetgen (Germany); Rainer Hilbig, Aachen (Germany); Achim Gerhard Körber, Kerkrade (Netherlands); Johannes Baier, Würselen (Germany); Klaus Gawron, Aachen (Germany); and Dieter Leers, Stolberg (Germany)
Assigned to Koninklijke Philips Electronics, N.V., Eindhoven (Netherlands)
Appl. No. 10/529,690
PCT Filed Sep. 23, 2003, PCT No. PCT/IB03/04156
§ 371(c)(1), (2), (4) Date Mar. 29, 2005,
PCT Pub. No. WO2004/032181, PCT Pub. Date Apr. 15, 2004.
Claims priority of application No. 102 45 922 (DE), filed on Oct. 02, 2002.
Prior Publication US 2005/0253521 A1, Nov. 17, 2005
Int. Cl. H01J 17/18 (2006.01); H01J 5/46 (2006.01)
U.S. Cl. 313—623  [313/624; 313/625; 313/626; 313/636; 313/318.01] 7 Claims
OG exemplary drawing
 
1. A high-pressure gas-discharge lamp, having at least one gastight fused press-seal between a glasslike material and molybdenum, wherein the molybdenum in the fused press-seal is at least partly exposed to an oxidizing environment and at least that part of the molybdenum that is exposed to the oxidizing environment is covered with a coating, characterized in that the coating comprises at least one oxide from among Fe2O3, Ta2O5, Nb2O5, Al2O3, SiO2, TiO2, ZrO2, HfO2, and a mixture of at least one nitride and at least one carbide wherein the nitride is selected from TiN, ZrN, HfN, AIN, BN, and wherein the carbide is selected from TiC, ZrC, HfC, VC, NbC, TaC, B4C, and further characterized in that the coating is built up from at least two layers, wherein (i) the layer of the coating that is applied directly to the molybdenum is an intermediate layer composed of the mixture, wherein the mixture is further characterized by nitrides and carbides with a quantitative ratio of nitrides to carbides which results in a coefficient of thermal expansion (CTE) of the intermediate layer having a value that is between that of molybdenum and that of a following layer and (ii) the following layer is composed of an oxide or a plurality of oxides.