Abstract:The phase morphology evolution during the solid solution treatment and then artificial aging of the La-modified ZL107 Al alloy was studied. The results show that when the solid solution was held at 560 °C for 6 h, only partial Si phase dissolved into the matrix; however, the precipitation also occurred during the artificial aging process. The precipitation process in Al−Si alloys with or without La-modification was compared. After modification and heat treatment, the mechanical properties of the alloy were greatly enhanced, due to the modification and uniform distribution of Si phase.

Key words: ZL107 aluminum alloys; modification; heat treatment; microstructure evolution; mechanical properties