Authors: SEVGİ ÖZDEMİR KART, MEHMET TOMAK, MUSTAFA ULUDOĞAN, TAHİR ÇAĞIN
Abstract: The rapid solidification of Pd-Ni alloys is studied with the constant-pressure and constant-temperature (TPN) and the constant-volume and constant-temperature (TVN) molecular dynamics technique to obtain an atomic description of glass formation in the alloy. Quantum Sutton-Chen potential for Pd-Ni binary system is applied in the simulations. We present some thermodynamic and structural results from simulations of such glasses over a range of compositions. The structural properties are analyzed by means of pair distribution function, volume, and enthalpy as a function of temperature and concentration at the cooling rates ranging from 5 K/ps to 0.05 K/ps to see whether the Pd-Ni alloy goes into glass formation or it crystallizes. The relation between the cooling rate and glass transition temperature is revealed. We have also investigated shear viscosity in the supercooled regime. Its temperature dependence indicates fragile-liquid behavior, typical of binary metallic glasses. The results shows that the atomic mismatch and having the eutectic composition are important parameters to form glassy state.
Keywords: Molecular dynamics, metallic glass, glass transition, fragility and Wendt-Abraham parameter.
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