Effects of pre-recovery treatment( 250 ℃ × 24 h + 300 ℃ × 6 h + 350 ℃ × 6 h + 400 ℃ × 6 h) prior to solid solution on microstructures and properties of extruded Al-13. 0Zn-3. 16Mg-2. 8Cu-0. 2Zr-0. 07 Sr alloy under T652 state were investigated by XRD and EBSD analyses,and electric conductivity,hardness,tensile,inter-granular corrosion and exfoliation corrosion tests. The results show that the pre-recovery treatment decreases the dislocation density,average grain size and average grain boundary angles,improv...