Thermodynamic description of the Nd-Fe-B ternary system

Abstract The Nd-B binary system was re-assessed thermodynamically based on the available experimental information from literatures using the CALPHAD method. The solution phases including liquid, fcc, bcc and dhcp, were modeled as substitutional solutions and their excess Gibbs energies were expressed by the Redlich-Kister polynomial. Combined with the previous assessments of the Fe-Nd and the Fe-B binary systems, the thermodynamic description of the Nd-Fe-B ternary system was performed on the basis of the reported experimental information. The solubility of third element in the binary intermetallic compounds was not taken into account due to the lack of experimental data. A set of self-consistent thermodynamic parameters formulating the Gibbs energies of various phases in the Nd-Fe-B ternary system was obtained in the present work. The liquidus projection, several isothermal sections and vertical sections of this ternary system were calculated, which are in reasonable agreement with the reported experimental data.