Mechanical properties of silver matrix composites reinfroced with ceramic particles

Purpose: Silver, silver alloys, as well as silver matrix based composites have been well known and applied in the electrotechnical and electronics industry for several decades. For many applications in electrotechnology, including electric contacts and brushes, unreinforced sliver alloys do not meet the requirements concerning mainly durability and wear resistance, first of all to tribological and electroerosive wear. These wear processes may be prevented by introducing to silver reinforcement particles and alloys. The target of the research included basic mechanical properties determination of the silver matrix composites reinforced with ceramic particles, manufactured with the use of suspension methods. Design/methodology/approach: In the presented paper the authors demonstrate possibilities of manufacturing of silver matrix composites on the way of casting technology utilization. Findings: The results of the research prove that applied suspension technology, based on introducing of agglomerated foundry alloy which is the carrier for reinforcement particles (SiC lub Al2O3) allows to produce in an effective and, what is important, in an economically attractive way, sliver alloys based composites. Research limitations/implications: The researches on the structure of manufactured composites and their mechanical properties that are presented in the paper prove the possibilities of mechanical mixing technology application for producing mechanical and stable connection between silver matrix and ceramic particles of aluminium oxide and silicon carbide. Originality/value: The manufacturing of this type of composites is based most of all on the utilization of powder metallurgy techniques. However the obtained results of the research prove that there is a possibility of silver matrix composites forming in the casting and plastic working processes. Extrusion process carried out in the hydraulic press KOBO has its favourably influence on ceramic reinforcement distribution, providing even distribution particles in matrix.