| 摘要 |
PURPOSE:To obtain an Ag-Nio electric contact point material excellent in workability and in consumption resistance by preparing, by an atomizing method, an Ag-Ni powder from molten Ag and Ni and by subjecting the above powder to internal oxidation, compacting, sintering and then plastic working so as to form into prescribed shapes and dimensions. CONSTITUTION:Ag to which prescribed amount of Ni is added is melted in a gaseous N2 atmosphere, from which the Ag-Ni powder is prepared by the atomizing method. Then the above Ag-Ni powder is subjected to classification to prepare the Ag-Ni powder in which Ni powder measuring from submicron to about several microns is dispersed. This Ag-Ni powder is formed into a block, which is subjected to oxidation under pressure, compacting and further pressure sintering in the air. Subsequently, the resulting sintered compact is subjected to hot compaction and then to drawing until the prescribed diameter is reached. In this way, Ni grains precipitate in Ag finely and uniformly and, resultingly, NiO is satisfactorily dispersed at the subsequent internal oxidation, so that the desired Ag-NiO electric contact point material excellent in consumption resistance can be obtained. |
