An advanced silver/tin oxide contact material

A new silver/tin oxide contact material is presented which is based on the utilization of tin oxide powders produced with the aid of the so-called “spray roasting” or “reaction spray” process. The contact properties of this new material were tested in a model switch as well as in commercially available contactors of different sizes and designs. The investigations carried out comprise tests of service life for different utilization categories, thermal behavior under continuous current, and welding on make. It was found, that by varying additives and production parameters in the “reaction spray” process for the tin oxide powders contact materials can be produced, which are superior in performance to conventionally manufactured p.m. type silver/tin oxide materials