EFFECT OF OXYGEN CONCENTRATION ON THE STRUCTURE AND PROPERTIES OF SINTERED SILVER-CADMIUM OXIDE COMPOSITE CONTACTS

The structure, corrosion resistance, and resistance to welding of silv er-cadmium oxide contacts fabricated by sintering powder compacts in a n inert gas containing a low concentration of oxygen were studied. Sin tering in the absence or deficiency of oxygen produced structural chan ges in the material, accompanied by a reduction in the volume fraction of cadmium oxide and formation of a solid solution of cadmium in the silver matrix. Lowering the oxygen concentration and raising the sinte ring temperature resulted in a redistribution of cadmium and oxide pha se in the solid solution, and impairment of the contact properties of the material. It appears that the effects observed are due to the deco mposition of cadmium oxide. New technology for the manufacture of cont acts by the powder metallurgical method is proposed, based an control of the oxygen concentration of the sintering atmosphere.