The development of silver-based cadmium-free contact materials

A systematic procedure for developing improved contact materials is presented. Utilization of the procedure is described in detail for the development of an improved silver-based cadmium-free contact material. The procedure involves electrical testing first of materials containing silver and major percentages of different oxide components. Based on these test results, the best major component is selected. A second test sequence is then conducted to evaluate the influence of minor percentages of different oxide additives on the performance of materials having the previously selected base composition. After selecting several of the most promising minor additives a complete series of device tests is run. The final selection of the best material composition is made based on these device test results. The cadmium-free material developed using this procedure is shown to exhibit superior weld resistance and lower erosion weight loss relative to a good-high-density P/M (powder metallurgy) silver-cadmium-oxide material.<>