The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 24, 2014
Filed:
Oct. 18, 2010
Akira Matsuo, Fukuoka, JP;
Yasutsugu Ueno, Fukuoka, JP;
Keiji Hara, Fukuoka, JP;
Keiichi Ozuka, Fukuoka, JP;
Shuichi Teramoto, Fukuoka, JP;
Akira Matsuo, Fukuoka, JP;
Yasutsugu Ueno, Fukuoka, JP;
Keiji Hara, Fukuoka, JP;
Keiichi Ozuka, Fukuoka, JP;
Shuichi Teramoto, Fukuoka, JP;
Nippon Tungsten Co., Ltd., Fukuoka, JP;
Abstract
A tungsten cathode material to be used for TIG welding, plasma spraying, plasma cutting, electro-discharge machining, discharge lamps, and the like is improved; use of the radioactive element thorium is reduced; and a long life and a high performance are realized. In a tungsten cathode material, oxide particles containing an oxide or oxides of at least one selected from the group consisting of Sm, Nd, Gd, and La in a total amount of 50 vol % or more are dispersed, the oxide particles having an average particle diameter d satisfying the relationship 0<d≦2.5 μm. Given a volume fraction f (vol %) of the total amount of the oxide particles in the tungsten cathode material, 0.083≦f/I holds when a current I(A) such that 0<I≦40 A is applied to an electrode being made of the tungsten cathode material.