Nonreactive wetting kinetics of binary alloys: A molecular dynamics study

The dynamic wetting of Cu-Ag binary alloys of different concentrations on rigid Ni surfaces is considered via molecular dynamics. The statics of wetting are studied with regard to the alloy concentration. The dynamic data (speed nu, dynamic contact angle theta) are compared to the Molecular-Kinetic model by a fitting procedure. To validate the fittings, the microscopic features of the mechanism are studied. The main parameter of this model (the equilibrium jump frequency K-theta) is calculated independently in the simulation. The two values, fitted and measured, are compatible, which extends the validity of the MKT theory for alloys. We also observe in our simulations Marangoni effects and Ag demixing in the formation of an adsorbed layer. Our results also seem to indicate that there is an optimum Cu-Ag binary alloy concentration for increasing the speed of wetting. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.