Influence of Chemical Composition and Production Process Parameters on the Structure and Properties of Silver Based Composites With ZnO / Ocena Wp?ywu Sk?adu Chemicznego Oraz Parametrów Wytwarzania Na Struktur? I W?a?ciwo?ci Kompozytów Na Osnowie Srebra Z Udzia?em ZnO

摘要

The paper shows results of the study into influence of chemical composition and consolidation process conditions on changes of physical and electrical properties of silver-based composites used in production of electric contacts. The investigations addressed influence of content of zinc oxide (ZnO) and modifying additions in a form of silver tungstate (Ag2WO4) and silver molybdate (Ag2MoO4) on changes in density, porosity and electrical conductivity. Density of the produced compacts was established by geometric method. The results of density measurements were used in determination of total porosity of sinters. Also arc erosion was examined to determine applicability of the produced composites for production of electric contacts. The erosion was measured as mass loss of individual materials after specific number of connections. The studies were conducted at current intensity of 10 A and voltage of 500V. The scope of the studies covered also evaluation of kinetics of sintering of the examined composites and determination of the mechanisms of mass transport in the process. Studies into kinetics of sintering were conducted in the air atmosphere at constant temperature of 900°C.