| 摘要 |
PURPOSE:To obtain a contact point material which has much higher welding resistance and does not contain harmful components by subjecting an Ag alloy which is added preliminarily with a small amt. of the element having the high rate of volumetric expansion by oxidation and contains a small ratio of Li and Pb to a heating treatment in an oxidation atmosphere to disperse the oxide of the Li and Pb into the Ag. CONSTITUTION:The Ag alloy contg. 0.05-3wt% Li and 3-6% Pb is subjected to the heating treatment at, for example, 700 deg.C in the oxidation atmosphere to disperse the Li and Pb in the form of the oxide into the Ag. The element having the high rate of volumetric expansion by oxidation is required to be preliminarily added into the above-mentioned alloy at 0.1-5wt% ratio by the total weight of the alloy. The internal stress of the resulted contact point material increases with the volumetric expansion of the added element so that the hardness and welding resistance thereof are improved. Preferably >=1 kinds among Si, Cu, Zn, Cd, Sn and Sb are used for the above-mentioned element to be added.
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