Three dimensional atom probe investigation on the formation of Al3(Sc,Zr)-dispersoids in aluminium alloys

Three dimensional atom-probe (3DAP) has been applied in order to study the nucleation of small, spherical and coherent Al-3(Sc,Zr)-dispersoids. The results indicate that Al-3(Sc,Zr) in the beginning of the nucleation process mainly consist of Al and Sc, while Zr enters the dispersoids at a later stage, i.e. relatively Zr-rich shells seem to form around Sc-rich cores. (C) 2004 Published by Elsevier Ltd. on behalf of Acta Materialia Inc.