Precipitation characteristics and morphological transitions of Al3Sc precipitates

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 Al 3 Sc precipitates. All the alloys were annealed at 450 °C for 2–1000 h, and Al 3 Sc 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 Al 3 Sc 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 Al 3 Sc precipitates and the precipitation behavior of Al 3 Sc based on changing the matrix composition.