Precipitation kinetic of Al3(Sc,Zr) dispersoids in aluminium

The non-isothermal formation of Sc- and Zr-containing dispersoids in Al–Zr–Sc ternary alloys has been investigated by atom probe tomography (APT). In the early stages of precipitation, a high number density of Sc-rich clusters form. These clusters subsequently transform into Al3Sc particles with a L12 structure. When Zr diffusion becomes significant, Zr atoms are found to segregate to Al3Sc/α-Al matrix interfaces. Further annealing at 748 K gives rise to a duplex core/shell structure.