Study on microstructure characterization, electrical conductivity and mechanical property improvement mechanisms of a novel Al-Si-Mg-Fe-Cu alloy

Abstract

A novel Al-4Si-0.8Mg-0.2Fe-0.1Cu with high strength, plasticity and electrical conductivity (EC) was developed successfully. The effects of Mg, Fe and Cu on microstructure, mechanical property and EC were systematically investigated. Interestingly, nano precipitates (nano AlFeSi and Mg2Si) not only acted as obstacles and sources of dislocation playing a precipitation strengthening role, but also the precipitation of AlFeSi and Mg2Si purified Al matrix to guarantee high EC. Thus EC and mechanical property of Al-4Si-0.8Mg-0.2Fe-0.1Cu alloy can be improved simultaneously. Results showed that EC of the alloy can reach 59.1%IACS (%IACS is short for International Annealed Copper Standard), the brinell hardness was 121 HBW, the ultimate tensile strength at room temperature (UTSRT) can reach 345 MPa and the corresponding elongation was 13%. The EC of Al-4Si-0.8Mg-0.2Fe-0.1Cu alloy was close to pure Al, and its corresponding mechanical properties were much higher than pure Al. So a kind of aluminum alloy conductive material with good EC and high strength was fabricated which has a certain application prospect in the field of overhead transmission line.