Method for producing composite powders based on silver-tin oxide, the composite powders so produced, and the use of such powders to produce electrical contact materials by powder metallurgy techniques

1. Field of the Invention A method for producing composite powders based on silver-tin oxide, by chemically reductive precipitation of silver onto particulate tin oxide. A solution of a silver compound and a solution of a reducing agent are simultaneously added in stoichiometrically equivalent amounts, separately and continuously with intensive mixing, to an aqueous suspension of tin oxide. The resulting composite powders have very high homogeneity, and can be processed to make electrical contact materials. The method is particularly suitable for producing composite powders based on silver-tin oxide doped with indium oxide, to be used in the manufacture of electrical contact materials.