Title :
The effects of metal oxide additions or dopants on the electrical performance of AgSnO2 contact materials
Author :
Jeannot, Didier ; Pinard, Jacques ; Ramoni, Pierre ; Jost, Ernest M.
Author_Institution :
Metalor SA, Neuchatel, Switzerland
Abstract :
The new contact material AgSnO2, which is replacing AgCdO in many applications, requires the addition of doping agents to improve electrical contact performance. These additions effect thermodynamic stability, wettability of the SnO2 surface by liquid silver as well as the microstructure of the area melted by the electric arc. This work considers the frequently used dopants WO3 , MoO3, Bi2O3, CuO and RuO2 as well as others: ZnO, Ta2O5, HgO, RuO2, Sb2O3, TeO2 and TaC. DTA and TGA analyses are performed on mixtures of these metal oxides with SnO2, Ag and AgSnO2. Reaction products, if present, are characterized by X-ray diffraction. The wetting angles of molten silver on surfaces of these mixtures are established. The results are used to interpret the microstructures found in the molten regions of AgSnO2 materials doped with these substances. These structures are interpreted and related to performance in arcing contact applications
Keywords :
X-ray diffraction; arcs (electric); circuit-breaking arcs; electrical contacts; silver compounds; thermal analysis; tin compounds; wetting; AgSnO2; AgSnO2 contact materials; DTA; TGA; X-ray diffraction; dopants; electric arc; electrical performance; metal oxide additions; molten silver; reaction products; surface microstructure; thermodynamic stability; wettability; Bismuth; Contacts; Doping; Microstructure; Performance analysis; Silver; Thermal stability; Thermodynamics; X-ray diffraction; Zinc oxide;
Conference_Titel :
Electrical Contacts, 1993., Proceedings of the Thirty-Ninth IEEE Holm Conference on
Conference_Location :
Pittsburgh, PA
Print_ISBN :
0-7803-1270-8
DOI :
10.1109/HOLM.1993.489660
