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 ?m. 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.

Abstract: Provided is a cathode material which becomes an alternative material of a cathode material formed of a W—ThO2 alloy and is formed of a tungsten alloy that does not include thorium which is a radioactive element. When particles of a rare earth oxide and tungsten carbide are finely dispersed in a tungsten cathode material used as a discharge cathode material used in TIG, plasma spraying, plasma cutting, electrical discharge machining, discharge lamps and the like, reduction and diffusion of the rare earth oxide are accelerated, and supply of rare earth elements to a cathode surface is ensured, thereby improving discharge characteristics.

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 ?m. 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.