EVOLUTION OF CORE-SHELL PRECIPITATES IN Al-Sc-Zr

A. J. TOLLEY; V. RADMILOVIC; U. DAHMEN

Bariloche

Congreso; Congreso SAM CONAMET 2018; 2018

ASOCIACIÓN ARGENTINA DE MATERIALES

In Al-Sc alloys, Al3Sc precipitates are formed that coarsen at a very slow rate. Ternary additions of Zr further reduce the coarsening rate. Precipitates in Al-Sc-Zr alloys form a core-shell structure with an Al3Sc core surrounded by an Al3(Sc,Zr) shell. The evolution of core-shell precipitates during high temperature annealing of an Al-Sc-Zr alloy was investigated using Z contrast high angle annular dark field (HAADF) imaging in scanning transmission electron microscopy (STEM). Both the shell and the core were found to grow with aging time and their volumes remained roughly proportional, even after prolonged aging.