The addition of 5% of bismuth oxide to an Ag-10% CdO powder composite enhances the erosion resistance of contacts made from it. Similar additions of tungsten and indium oxides adversely affect, and one of tin oxide has but little effect on, the erosion resistance of Ag-15% CdO composite contacts. Bismuth oxide and, to an even larger extent, indium oxide improve the resistance to welding of these contacts. The effect of the oxides on the structure and resistance to erosion and welding of the contacts is determined by their ability to react with the components of the matrix and by the properties of the reaction products.