| 摘要 |
PROBLEM TO BE SOLVED: To prevent the strength deterioration in a welding portion and the thermal deformation of a cathode support body by forming the cathode support body of a high-melting point metal core material and metal material having lower melting point than that, and covering the fixing portion of the cathode support body and a cathode sleeve. SOLUTION: In an impregnation type cathode structure, a cathode support cylinder 25 is coaxially arranged outside a cathode sleeve 21. Plural cathode support bodies 26 are arranged inside the cathode cylinder 25 at positions, spaced at intervals in a circumference direction. The cathode support body 26 is composed of a core material 261 which is made of circular wire rods in cross sections, formed of high-melting point metal having strong high temperature strength, and covering material 262 which is formed, so as to cover the core material 261 and is made of metal having a lower melting point than that of the core material 261. The covering material 262 is fixed to one end of the cathode support body 26, and the core material 261 is fixed to the cathode sleeve 21. The core material 261 is selected from among W, Mo, Re, Ta, Nb, Ir or an alloy of these. The covering material 262 is selected from among Pt, Rh, Pd, V, Au, Ti or an alloy of these. |
