Changes in properties of aluminium matrix composite reinforced with SiC particles after multiple remelting

摘要

Following the EU environmental regulations (e.g. Directive 2000/53/EC of the European Parliamentnand of the Council of 18 September 2000 on end-of-life vehicles), there is a need for informationnregarding the behaviour of materials during different recycling treatments before the introductionnof new products in industry. This research is devoted to the scientific and practical aspects ofnrecycling of cast metal matrix composites (MMCs) that among other applications, are used in carnvehicles in steadily increasing numbers. The analysis of conditions for MMC remelting and theneffects of number of remelting cycles on selected physical and mechanical properties has beennperformed on aluminium matrix composite (A359 aluminium alloy reinforced with 10 vol.%SiCnparticulates). After each remelting operation, structural characterisation as well as thenmeasurements of electrical conductivity, density, hardness (HBW), ultimate strength (Rm),nYoung’s modulus (E), elongation (A), yield limit (R0?2), elastic limit (R0?05) and wear resistancenwere carried out and compared with investigations of as-received composite material. Fornmultiple remelting (up to nine remelts), structural observations by optical microscopy did notndemonstrate any remarkable changes, compared to as-received composite. Moreover, there wasnno significant degradation of SiC particles. At the same time, a continuous decrease in utilitynproperties of composite material with increasing number of remelting cycles was recorded,nshowing their tolerable reduction after the ninth remelting.