Abstract:Effect of solution temperature on solid solubility, tensile properties, microstructure and fractography of a new Al-Zn-Mg-Cu-Zr aluminum alloy were studied by tensile testing, optical microscopy, XRD, SEM and EPMA. The results indicated that the solid solubility of matrix increase with the increasing temperature, and when it reach stable state at 474℃, about 99 wt.%Zn, Mg and 75 wt.%Cu enter matrix, the residual elements enrichment in the second phase particles（T phase）located on grain boundary. The optimal solution temperature is 474℃, the tensile strength of forge can get up to 688MPa, and elongation is 8%. At 476℃, the slight over-burned in local region is observed, which lead to the decrease of elongation rapidly. It is found that the tensile fractography was affected by the volume fraction of residual particles and the recrystallization level of deformed grains. With the temperature increasing, the fractography transform from intergranular cracking mixed dimple-type transgranular cracking to intergranular cracking.