LAUSR

Abstract In present study, the effect of the loading orientations on the precipitation characteristics of precipitates were studied during stress aging of Al-Cu-Mg-Ag alloy using single crystals with various orientations. The microstructures were characterized by means of HAADF-STEM observed along multiple and zone axes, while the mechanical property is represented by the hardness test. The results show that the precipitation characteristics of the precipitates are significantly affected by the loading orientation. The length of the Ω-phase in the sample loaded along direction is more uniform than that of the sample loaded along direction, and both of two samples have high number density of Ω precipitates. On the contrary, the precipitation of Ω-phase is significantly suppressed and the Ω precipitates are extremely rare in the sample loaded along direction. This study proposes a strategy to regulate the precipitation of the Ω-phase in Al-Cu-Mg-Ag alloy system by controlling the loading orientation during stress aging or creep aging.