EP 1555331 A1 20050720 - High ductility, high hot tensile strength tungsten wire and method of manufacture
Title (en)
High ductility, high hot tensile strength tungsten wire and method of manufacture
Title (de)
Hochumformbarer und Hochwarmfestiger Wolframdraht sowie Verfahren zur dessen Herstellung
Title (fr)
Fil de tungsten à haute ductilité et haute resistance a traction a chaud et son procédé de fabrication
Publication
Application
Priority
US 75964504 A 20040116
Abstract (en)
A method for manufacturing a high ductility and high hot tensile strength tungsten wire (9) for incandescent lamp filaments is disclosed. The method comprises the steps of preparing a tungsten alloy, swaging a tungsten rod from the alloy, and drawing the swaged rod to wire size in multiple drawing passes. In the method, the wire (9) is annealed between predetermined draws. It is proposed that an annealing is performed before the final drawing pass, by annealing the wire at a temperature between 1100-1300 DEG C. <??>There is also provided a tungsten wire (9) for incandescent lamp filament, which has high ductility and high hot tensile strength. The tungsten wire (9) of the invention has a cold tensile strength - hot tensile strength ratio not exceeding 3.5. <IMAGE>
IPC 1-7
IPC 8 full level
B21C 1/00 (2006.01); B21C 37/04 (2006.01); C22C 27/04 (2006.01); C22F 1/18 (2006.01); H01K 1/08 (2006.01); H01K 3/02 (2006.01); H01K 3/04 (2006.01)
CPC (source: EP US)
B21C 1/003 (2013.01 - EP US); B21C 37/045 (2013.01 - EP US); C22C 27/04 (2013.01 - EP US); C22F 1/18 (2013.01 - EP US); H01K 1/08 (2013.01 - EP US); H01K 3/02 (2013.01 - EP US); H01K 3/04 (2013.01 - EP US)
Citation (search report)
- [X] WO 03031668 A1 20030417 - TOSHIBA KK [JP], et al
- [X] US 6419758 B1 20020716 - BEWLAY BERNARD PATRICK [US], et al
- [A] US 2002145373 A1 20021010 - MESZAROS ISTVAN [HU], et al
- [A] US 6190466 B1 20010220 - APAGYI JOZSEF [HU], et al
- [A] EP 0765949 A1 19970402 - OSRAM SYLVANIA INC [US]
- [A] US 2489912 A 19491129 - LILLIENDAHL WILLIAM C
- [A] US 3236699 A 19660222 - PUGH JOHN W, et al
- [A] URAY L: "AKS doped tungsten--investigated by electrical resistivity I. Manufacturing tungsten bar and wire", INTERNATIONAL JOURNAL OF REFRACTORY METALS AND HARD MATERIALS, ELSEVIER PUBLISHERS, BARKING, GB, vol. 20, no. 4, July 2002 (2002-07-01), pages 311 - 318, XP004390757, ISSN: 0263-4368 & EP 1435398 A1 20040707 - TOSHIBA KK [JP]
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 1555331 A1 20050720; EP 1555331 B1 20071114; DE 602005003240 D1 20071227; DE 602005003240 T2 20080911; US 2005155680 A1 20050721; US 2008135139 A1 20080612
DOCDB simple family (application)
EP 05250198 A 20050114; DE 602005003240 T 20050114; US 75964504 A 20040116; US 83981307 A 20070816