|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Computational Thermodynamics and Kinetics
||A Molecular Simulation Study of the Effect of Composition Gradients on Intermetallic Nucleation
||Peng Yi, Michael L. Falk, Timothy P. Weihs
|On-Site Speaker (Planned)
DSC and TEM experiments in the Ni/Al multilayer system have suggested that the formation of certain intermetallic phases can be suppressed by a sharp composition gradient across the Ni/Al interface, giving other intermetallic phases the opportunity to form instead. We studied the effect of a composition gradient on the nucleation of NiAl intermetallic phase from amorphous solutions in the Ni/Al system using molecular dynamics simulations and a semi-empirical EAM potential. We observed that crystallization of NiAl intermetallic was deferred by the presence of a composition gradient. Important thermodynamic quantities including the melting point, interfacial free energy and critical nucleus size were calculated to estimate the thermodynamic driving force as a function of concentration gradient. These calculations were used to validate and develop a classical nucleation theory formulation that incorporates the composition gradient effect, originally proposed by Desre and Yavari (1990).
||Planned: Supplemental Proceedings volume