© Copyright by International OCSCO World Press. All rights reserved. 2008 VOLUME 26 ISSUE 2 February 2008 Short paper 123 of Achievements in Materials and Manufacturing Engineering of Achievements in Materials and Manufacturing Engineering Silver – mishmetal alloy for application at elevated temperature W. Głuchowski a, *, Z. Rdzawski a,b a Institute of Non-Ferrous Metals, ul. Sowińskiego 5, 44-100 Gliwice, Poland b Division of Materials Processing Technology, Management and Computer Techniques in Materials Science, Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, 44-100 Gliwice, Poland * Corresponding author: E-mail address: wojtekg@imn.gliwice.pl Received 20.12.2007; published in revised form 01.02.2008 Materials AbstrAct Purpose: The aim of this work was to investigate the changes taking place in the structure and properties of silver - mishmetal alloys caused by severe plastic deformation compared to the Ag+(7.5 wt %)Cu alloy and pure Ag materials. Design/methodology/approach: Tests were made with samples obtained by melting and casting in an induction furnace. Further plastic working included KOBO® extrusion process and drawing. The mechanical properties (at a room temperature, elevated temperature and after annealing) and microstructure were examined (by the optical, scanning and transmission electron microscopy). Findings: Structure of the extruded material was fine and homogenous. The alloys with an addition of mishmetal had high electrical conductivity, which was decreasing with an increase in the content of alloy additives. Examination of the mechanical properties has shown that these alloys exhibited (after annealing) an increased stability of properties at elevated temperatures. Practical implications: The alloy with an addition of mishmetal could be considered, after further investigations, as a material suitable for use in the production of electrical or electronic parts operating at elevated temperature or exposed to temperature changes. Originality/value: This work demonstrated that properties of the newly designed silver alloys with an addition of mishmetal exhibit temperature stability . The wire made from this material could be easily produced by the developed processing methods, without the need to use annealing operations. Due to the stable properties and excellent electrical conductivity, this alloy is suitable for use in the production of an advanced electrical or electronic equipment. Keywords: Metallic alloys; Functional materials; Metallography; Electrical conductivity 1. Introduction Most of the world silver consumption is in electronic and electrical industry (40% in 2003), most often as conductors and contacts [1,2]. Some of them are designed for operation at elevated temperatures or are exposed to periodic temperature changes. Pure silver cannot be used for these applications because of its insufficient mechanical properties and low softening temperature [3,4]. Suitable mechanical properties can be obtained when alloy additives are used, particularly such which cause precipitation hardening [5-12] or dispersion hardening [13-15]. However, this results in a decrease of electric conductivity and very often in a decrease of tarnish resistance. It is expected that an addition of mishmetal to silver based alloys may contribute to grain size refinement. Due to the presence of hard intermetallic phase particles, this structure 1. Introduction