Effect of Heat Treatment on Microstructures and Mechanical Properties of Al-9.0Zn-2.5Mg-1.2Cu-0.12Sc-0.15Zr Alloys
The microstructures and mechanical properties of Al-9.0Zn-2.5Mg-1.2Cu-0.12Sc-0.15Zr alloys under different treatment conditions were investigated by hardness test,tensile properties,electric conductivity,DTA and X-ray analysis.The result shows that the peak aging occurs at 120℃ for 22h.When the aging treatment is RRA treatment(Retrogression and Re-ageing): 120℃×22h+180℃×30min+120℃×22h,the synthetic properties is best.At this condition,the tensile strength,elongation and electric conductivity of studied alloy are 733.4 MPa,5.44%,37.6%IACS.