Improved Ag-SnO_2 Electrical Contact Material Produced by Mechanical Alloying

摘要

Very pure electrical contact material Ag-SnO_2composite powders have been produced by mechanical alloying(MA). The starting powders-the silver tin alloy Ag_3Sn and silveroxide Ag_2O-were mixed in a specific concentration ratio andthen milled by the use of a 'Simoloyer'(horizontal rotary ballmill). During the milling process a chemical reaction takes placeand simultaneously a mechanical alloying is carried out whichleads to a high dispersed phase distribution of nanoscaled SnO_2-particles in a silver matrix. The influence of milling parameterson the milling process such as temperature, atmosphere, rotaryvelocity and ball/powder ratio were studied to optimize theprocess. It has been found that the temperature is the mostsignificant factor to vary the milling time. The as-milled powdershave been characterized by scanning electron microscope (SEM),transmission electron microscope TEM and X-ray diffraction (XRD).