Ag中にMg, Mn, Laの酸化物を分散させた接点について

Abstract

Silver base alloys containing magnesium-, manganese- and lanthanum-oxide were prepared by the internal oxidation in air at 650°C. The characteristics of erosion resistance, welding resistance and contact resistance of these contacts have been measured under the conditions of an applied voltage of 100 volts and circuit currents from 10 to 50 amperes in alternating current.The addition of lanthanum oxide is very effective to improve these characteristics. The contacts containing lanthanum oxide (0.5 at%La) have higher welding resistance and lower contact resistance than the silver-12 wt% cadmium oxide contact which is used very frequently, both contacts are comparable in erosion resistance. On the other hand, although the additions of magnesium and manganese oxides are not so good as that of lanthanum oxide, the erosion resistance of magnesium oxide (1.0 at%Mg) and manganese oxide (3.2 at%Mn) contacts are comparable with that of 12 wt% cadmium oxide contact in the high current region over 30 amperes. Furthermore, the change of the amount of erosion with current becames small for magnesium oxide and manganese oxide contacts.