Effect of Artificial Aging Temper on the Microstructure and Properties of 7B04 Pre-Stretched Thick Plate

Abstract

One- and two-step artificial aging had been performed on the 7B04 pre-stretch thick plate, whose nominal composition is similar to 7075 alloy with lower Fe and Si content. The effect of aging temper on the microstructure and properties has been studied. The research results show that T6 temper can improve the mechanical properties of the alloy greatly, yet the alloy have lower electron conductivity which is no more than 19Ms·s-1. When T73 and T74 tempers were performed on the alloy, the mechanical properties of the alloy decreased about 6~10% of the T6 strength while the electron conductivity was improved obviously. With the increasing of the aging temperature, the time that the alloy needs to get peak aging becomes shorter and the mechanical properties at peak aging status are lower. The electron conductivity of the alloy, however, becomes higher with the increasing of aging temperature. The main strengthen phase of 7B04 alloy is also η(MgZn2) phase which is same to other 7xxx series alloys.