Experimental study and thermodynamic assessment of the Ni-Mo-Ta ternary system

Phase equilibrium data of the Ni-Mo-Ta system at 1473, 1373, and 1173 K were determined by means of diffusion triple and electron probe microanalysis (EPMA) techniques in this article. From the present experimental results and Literature data, the Ni-Mo-Ta system was thermodynamically assessed using the CALPHAD method. A set of consistent thermodynamic parameters of each phase was obtained. A number of calculated isothermal sections are presented and compared with experimental data. They are in reasonable agreement. The present calculation was successfully used to analyze the solidification behavior of two alloys. Two subsystems, Ni-Mo and Mo-Ta, were assessed prior to the assessment of the ternary system.