During solution treatment,Cu-based phases were completely dissolved,while the eutectic Si and Mg-rich phases experienced partial dissolution. Some of the Mn-rich phases were partially dissolved while the Al59.2Si9.2CuFe3.4Mn6.3 compound transformed to Al15(FeMn)3(Si)2. The Mn-modified alloy after T6 heat treatment achieved an elongation of 13.5%with an ultimate tensile strength of 355MPa,which is 18MPa higher than the Mn-free base and 30% higher than the A319 alloy after similar heat treatment.The fatigue life of the Mn-modified alloy was also substantially longer than that of the reference base and the A319 grade.