LAUSR

Abstract Al-xMg-0.3Sc (x = 0, 3%, 5%) alloys with different Mg contents were designed to study the effect of Mg on the precipitation characteristics and morphological transitions of Al3Sc precipitates. All the alloys were annealed at 450 °C for 2–1000 h, and Al3Sc precipitates were observed by transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The results show that the addition of Mg has various effects on the precipitation behavior of Al3Sc precipitates. Notably, Mg addition increases the critical dimension for the loss of coherency and retards the morphological evolution from spherical to cuboidal. These findings provide a new reference for studies of Al3Sc precipitates and the precipitation behavior of Al3Sc based on changing the matrix composition.