Characteristics for the Electrical Contact of Silver Base Alloys Containing Two Kinds of Oxide out of Magnesium, Manganese, Lanthanum and Zirconium Oxides

Abstract

Four silver base alloys containing two kinds of oxide, namely, manganese and zirconium oxides, magnesium and zirconium oxides, magnesium and lanthanum oxides, and lanthanum and zirconium oxides, are prepared by the internal oxidation in air at 650°C. The characteristics of the erosion resistance, the welding adhesion resistance and the contact resistance as the electrical contact have been investigated with them under an applied voltage of 100 V and amperage from 10 to 50 A in alternating current.
The coexistence of zirconium oxide with the others is very effective for improving the welding adhesion resistance. Comparing with the characteristics of silver-12 wt% cadmium oxide contacts which are generally used, the contacts containing lanthanum and zirconium oxides (0.40 at% La and 0.49 at% Zr) have the higher welding adhesion resistance and a little lower erosion resistance, and those containing magnesium and zirconium oxides (0.49 at% Mg and 0.50 at% Zr) have almost the same erosion resistance and welding adhesion resistance. Furthermore, these contacts are comparable in contact resistance to each other. On the other hand, the erosion resistance of the silver base contacts containing manganese and zirconium oxides (2.0 at% Mn and 0.96 at% Zr), magnesium and zirconium oxides (0.49 at% Mg and 0.50 at% Zr) and magnesium and lanthanum oxides (0.49 at% Mg and 0.36 at% La) is improved in the high current region, because the dependence of the amount of erosion on the testing current is less than that of other contacts.