PURPOSE: To provide a contact material presenting excellent stability in the current cut-off characteristics and re-arcing characteristics by mixing Cu2O fine powder with WC/W fine powder, molding the resultant mixture. selectively reducing Cu2O in a hydrogen gas atmosphere, and subjecting the obtained skeleton to infiltration with Ag and Cu.
CONSTITUTION: Fine powder of Cu2O is mixed with fine powder of WC or W, and the mixture is molded under pressure. The obtained molding is sintered hydrogen gas atmosphere, and Cu2O is selectively reduced to make a skeleton of (Cu+WC) or (Cu+W). The electric conductive component of Ag, Cu, or Ag-Cu alloy is infiltrated in voids in the skeleton to produce a contact material for a vacuum valve. The longer diameter of particle of Cu2O, WC, W should preferably range 0.3-10μm while the shorter diameter range 0.2-5.0μm. The mixing ratio of the powder should preferably be 5-50wt.% Cu2O and 50-95% WC or W.
KUWABARA KAZUYOSHI
OKUTOMI ISAO
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