Crystallization and nucleation in liquid Al containing spinel seeds
Write By Reza Haghayeghi
Haghayeghi, M. Qian, “Crystallization and nucleation in liquid Al containing spinel seeds”, Materials Letters, 196 (2017) 358–360.
Step-by-step in situ near-atomic-resolution observations were presented for initial crystallization or nucleation in a liquid Al-10Mg (wt%) alloy containing spinel (MgAl2O4) seeds. Ordering of Al atoms was observed in the alloy at the interface with spinel at the superheat of 73 oC or at the melt temperature of 680 oC, where three ordered layers of Al atoms formed and disappeared alternately. When cooled to
the approximate liquidus of the alloy, 607 oC, three similar but more stable ordered layers of Al atoms formed. Subsequent crystallization occurred first through the formation of partially close-packed Al atoms on the solid-like outer ordered layer of Al atoms, followed by further crystallization into more close-packed Al atoms.
