An experimental and theoretical study of the phase equilibria in the Fe-Mo-Ni system

Abstract

New experimental data on the Fe-Mo-Ni phase diagram have been obtained at 1223, 1273, 1373, 1473, and 1543 K using a diffusion couple technique. A number of tie lines were determined using a scanning electron microscope with energy-dispersive X-ray analysis equipment. In a few cases, the phases were identified by X-ray diffraction. The experimental data obtained in the present work, and previously published data, were analyzed by the use of thermodynamic models describing the Gibbs energy of the various phases. The model parameters were calculated using a computerized optimization procedure. The intermetallic phases stable at temperatures above 1223 K were included in the calculations using a three-sublattice model. Experimental data on solidus and liquidus temperatures were used to evaluate properties for the liquid phase. A number of calculated isothermal sections are presented and compared with experimental data. The calculations satisfactorily describe the available experimental data.