Microstructure refinement and physical properties of Ag-SnO2 based contact materials prepared by high-energy ball milling

• Published in: Science of sintering Vol. 45; no. 2; pp. 173 - 180
• Main Authors: Cosovic, V, Pavlovic, M, Cosovic, A, Vulic, P, Premovic, M, Zivkovic, D, Talijan, N
• Format: Journal Article
• Language: English
• Published: International Institute for the Science of Sintering, Beograd 2013
• Subjects: Ball milling; Contact; Dispersions; Electric contacts; high-energy Ball milling; Metal oxides; Microstructure; Physical properties; powder metallurgy; Silver; silver-metal oxide electrical contacts
• ISSN: 0350-820X; 1820-7413
• DOI: 10.2298/SOS1302173C

High energy ball milling was used to improve dispersion of the metal oxide in Ag-SnO2 electrical contact materials. The processed Ag-SnO2 (92:8) and Ag-SnO2-In2O3 (87.8:9.30:2.9) powder mixtures were subsequently consolidated to bulk solid pieces by conventional powder metallurgy. The microstructure of the prepared samples was analysed by XRD and SEM, and properties such as density, hardness and electrical conductivity were measured. X-ray analysis results indicated a reduction of crystallite size after milling of about ten times. The microstructures of the sintered Ag-SnO2 and Ag-SnO2-In2O3 materials displayed very fine dispersion of the oxide components in the silver matrix. Somewhat higher uniformity was obtained for the Ag-SnO2-In2O3 material as shown by results of SEM analysis and more consistent microhardness values. The obtained values of the physical properties were found to agree with the observed higher dispersion of metal oxide particles and were comparable to properties of commercial electrical contact materials of this type.