Heat-resistant Al–0.2Sc–0.04Zr electrical conductor

Abstract

The combined effects of ageing and cold-rolling on the tensile and conductive properties of Al–0.2Sc–0.04Zr alloys were investigated. Both the tensile strength and electrical conductivity of alloys after cold-rolling+ageing or pre-ageing+cold-rolling+ageing treatments are apparently better than that of the only aged alloy; furthermore, the improvements on the properties made by pre-ageing+cold-rolling+ageing are slightly greater than that by cold-rolling+ageing. TEM observations indicate that the increase of strength should be associated with the formation of finer Al3(ScZr) precipitates and substructure with boundaries pinned by nano-sized precipitates while the improvement of conductivity should be caused by the closure of microvoids. As an electrical conductor, the highest working temperature of Al–0.2Sc–0.04Zr with the best strength and conductivity can be as high as 345°C. It strongly suggests that the Al–Sc–Zr alloy has a great application prospect in heat resistant conductor fields.