Investigation of partitionless growth of epsilon-Al60Sm11 phase in Al-10at% Sm liquid

Y Sun and Z Ye and F Zhang and ZJ Ding and CZ Wang and MJ Kramer and KM Ho, MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING, 26, 015006 (2018).

DOI: 10.1088/1361-651X/aa9747

Recent experiments on devitrification of Al90Sm10 amorphous alloys revealed an unusual polymorphic transformation to a complex cubic crystal structure called the epsilon-Al60Sm11 phase. Molecular dynamics simulations of the growth of the stoichiometric e-phase seed in contact with an undercooled Al-10 at% Sm liquid are performed to elucidate the microscopic process of transformation. The as-grown crystal and undercooled liquid possess similar local order around Al atoms whereas a rigid network defined by the Sm sub-lattice develops during the growth. Using a template-cluster alignment method, we define an order parameter to characterize the structural evolution in the system. Estimates of the attachment rate is Ra= 8.70 x 10(-4) angstrom(-2) ns(-1) and detachment rate is R-a= 3.83 ' 10(-4) -angstrom(-2) ns(-1) at the interface between epsilon-Al60Sm11 and Al-10 at% Sm liquid at 800 K.

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