Rapid solidification of Cu25at.% Ni alloy: molecular dynamics simulations using embedded atom method

We have performed molecular dynamics simulations on rapid solidification of Cu25at.% Ni alloy based on the analytic embedded atom model for alloys. Our results, from the Faber—Ziman structure factors being consistent with experiments by Waseda, show that the present EAM potentials for Cu25at.% Ni alloy can correctly describe interactions between atoms (CuCu, CuNi and NiNi pairs), although the model parameters are obtained from only pure metals. Furthermore, we have examined structure evolution during rapid solidification based on some specific structure functions, such as the pair correlation function, the bond orientational order, the pair analysis techniques and the angular distribution function. Results show that with decreasing temperature, icosahedral ordering has been enhanced, and the fast cooling supports the local five-fold symmetry, the HCP- and FCC-types of atomic bonded pairs rather than the BCC-type of bonded pairs. In addition, we have examined several polyhedral distributions, such as the icosahedra, defective icosahedra etc., generated in the simulations.