Microstructure and Properties of an Al-7.5Zn-1.5Mg-1.4Cu-0.12Zr Alloy Forging

Abstract

In this present work, the microstructure and properties of an Al-7.5Zn-1.5Mg-1.4Cu-0.12Zr alloy forging in T7452 condition has been investigated by means of OM, TEM and EBSD analysis and varied properties test. The results indicate that there are obvious differences in grain morphology, precipitation characteristics and recrystallization degree along the thickness direction of the forging. The strength of the alloy forging is stable and varies less than 10% along the thickness direction. The alloy forging in the T7452 condition shows high strength, high toughness and good corrosion resistance, with the UTS, TYS, elongation and electrical conductivity values being 500~530 MPa, 460~500 MPa, 7.0~15.0% and 23.9~24.2 MS/m, respectively, and the fracture toughness in L-T, T-L and S-L direction being 33.5~39.5, 25.5~27.0, 23.0~24.5 MPa.m1/2, respectively, and the EXCO rating being EA.