WEB Pressure effects on Alloy Phase DiagramsWednesday (23.09.2020) 11:20 - 11:35 M: Modelling and Simulation 1 Part of:
The phase diagrams of binary alloys have been found to vary with pressure. Within the framework of solution-type models, the variation is controlled by the pressure dependence of the elemental end members, which is relatively well known, and that of the excess interaction, which is relatively unknown. Exact thermodynamic relationships for the pressure and temperature dependence of the interaction parameters in an alloy solution are developed and related to the composition dependence of the excess thermodynamic quantities measured at ambient conditions. The effect of pressure modification of selected phase diagrams (e.g Bi-Sb, Ga-In, Pb-Bi) is explored within this model. Significant changes in the phase diagram, including shifts of the eutectic points and transition from isomorphous to eutectic diagranms, are predicted. The model predictions are compared with experimental determinations of the effect of pressure on the phase diagram, e.g. by resistivity measurements in a Paris-Edinburgh cell.