Effects of Cu concentration on microstructure and tensile properties of high-Zn-content Al–Zn–Mg–Cu alloys

The effects of Cu concentration on microstructure and tensile property of the Al-18Zn-xCu-2.0Mg-0.12Ti-0.4Zr-0.25Sc-0.25Y (x=0.5 wt%, 1.0 wt%, 2.0 wt%) alloys were investigated. The results showed that the precipitation process from the GP zone to η was expedited with increasing Cu concentration, necessitating careful control to enhance the material properties. Optimizing the Cu concentration can lead to superior tensile properties. The alloy with 0.5 wt% Cu exhibited a high tensile yield strength of 626 MPa and a 6% elongation. •The Al-18Zn-xCu-2.0Mg-0.12Ti-0.4Zr-0.25Sc-0.25Y (x=0.5 wt%,1 wt%,2 wt%) alloys were prepared.•The effect of Cu concentration on microstructure and tensile property was investigated.•The precipitation process from G.P. zone to was promoted by increasing Cu concentration.•The alloy with 0.5% wt%Cu has the highest yield strength of 626 MPa with 6% elongation.•The strength-ductility synergy is promising.