Synthesis of silver tin oxide nano composite powders by coprecipitation method

Silver–metal oxide has various applications in manufacturing of contact materials. Although Ag/CdO contact materials are considered as reliable compounds, because of environmental problems, they are replaced by new compounds such as AgSnO2. Silver tin oxide materials are not only environment-friendly substances, they have also high temperature rise, contact resistance, hardness and well anti-welding and anti-arc erosion properties. There are some different methods for manufacturing them such as powder metallurgy, internally oxidation and chemical processes and so on. In the chemical coprecipitation method, silver and tin nitrate compounds were precipitated in carbonate media. Dried powders were calcinated at 550°C. The nanocmposite powders and microstructures of prepared contact materials were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and x-ray mapping. The results showed that nanosized particles were achieved by this method. Also the homogenous distributions of tin oxide particles in silver matrix were observed. The efficiency of reactions was raised by substituting Sn by SnCl2.2H2O compound.

Keywords:

silver tin oxide , contact materials , coprecipitation , nanosized particles , tin nitrate