Analysis of the microhardness, mechanical properties and electrical conductivity of 7055 aluminum alloy

Abstract In order to explore the preaging process on the mechanical properties, electrical conductivity and precipitated phase of 7055 aluminum alloy, the influence of preaging process on mechanical properties and conductivity of 7055 aluminum alloy was studied based on microhardness testing, conductivity testing and tensile testing. The results show that the hardness peak aging of 7055 aluminum alloy is negatively correlated with the preaging temperature; In the low temperature preaging stage (the temperature is below 150 °C), the electrical conductivity of 7055 aluminum alloy and aging temperature presents negative correlation; In the high temperature preaging stage (170 °C–210 °C), the electrical conductivity of 7055 aluminum alloy and aging temperature appear positive correlation relationship. The aging process of 7055 aluminum alloy can be described as: α (Supersaturated solid solution) → G.P.zone → η phase → η ' → η phase.The degree of incoherency and size and preaging time presented obvious positive correlation, the larger the preaging time is, the larger the size of the precipitate phase gets, and the greater the incoherency between the precipitated phase and the substrate is.