Investigation of transformation from amorphous state to crystalline state for transition metal alloys by molecular dynamics method

In this study, interatomic interactions have been modeled by using Sutton-Chen version of embedded atom method for Cu and Ni mono-atomic systems, CuNi, NiAl binary alloy systems and CuAlNi ternary alloy system. Model systems have been investigated by the molecular dynamics (MD) simulation technique of Parinello-Rahman which allows the MD cell to vary in shape and size. Structural analyses during the phase transformations of all the model systems have been investigated using radial distribution function. The transformations of the model systems from liquid phase to amorphous phase with a high cooling rate have been performed, and the transformations to crystal phase have been analyzed by holding the amorphous phase at different temperatures. During these transformations processes, structures of atomic clusters have been determined using the bond orientational order parameters and Honeycutt-Andersen (HA) method. Variations in the percentages of the bonded pairs in the crystals have been investigated during the crystallization period for ternary alloy, and Avrami exponential values in Johnson-Mehl-Avrami (JMA) equation have been calculated for two different annealing temperatures using MD method. As a result, during the transformation from amorphous phase to crystalline phase, it has been determined that the bonded pairs and the bonded triples have an important role in the formation of crystal phase.