To improve reliability and productivity of a vacuum valve, by manufacturing the vacuum valve by applying a specific working process, heat treating process and brazing process relating to a specific contact material, and removing and reducing product and an attached object reduced on a contact piece surface.
A contact material is constituted by an arc resistant component containing 1 to 75wt.% at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Y and by the rest of conductive component composed of at least one or Cu, Ag. As the first process, this material, while controlling a temperature so as to prevent exceeding 70°C, is worked into a preset piece of prescribed shape. As the second process, this contact piece is high temperature heat treated under the vacuum atmosphere at a pressure of 8×10-5 to 5×10-7Torr range, at a 800 to 1050°C temperature for 5 minutes or more treating time. As the third process, the contact piece is brazed and air-tightly seal connected at a temperature not exceeding 1050°C in a 5×10-5Torr in vacuum, to obtain a contact for a vacuum valve.
SUZUKI HIDEO
SEKI KEISEI
YAMAMOTO ATSUSHI
KUSANO TAKASHI
TOSHIBA CORP