Figure 4. APT atom map (a) along with the one-dimensional concentration profiles (b) of a duplex precipitate in the high nickel alloy after aging at 500°C for 2000 h.

Both atom maps and concentration profiles show that Cu mainly enriched at the precipitate core, whereas Ni and Al along with Mn atoms were expelled away from the small Cu-rich core, resulting in the formation of the NiAl(Mn) phase.