Improved Ag-SnO2 electrical contact material produced by mechanical alloying

Very pure electrical contact material Ag-SnO2 composite powders have been produced by mechanical alloying (MA), The starting powders - the silver tin alloy Ag3Sn and silver oxide Ag2O - were mixed in a specific concentration ratio and then milled by the use of a 'Simoloyer' (horizontal rotary ball mill). During the milling process a chemical reaction takes place and simultaneously a mechanical alloying is carried out which leads to a high dispersed phase distribution of nanoscaled SnO2-partides in a silver matrix, The influence of milling parameters on the milling process such as temperature, atmosphere, rotary velocity and ball/powder ratio were studied to optimize the process. It has been found that the temperature is the most significant factor to vary the milling time. The as-milled powders have been characterized by scanning electron microscope (SEM), transmission electron microscope TEM and X-ray diffraction (XRD).