Thermodynamic description of the Nd-Fe-B ternary system

Magnetic-Property Assessment on Dy–Nd–Fe–B Permanent Magnet by Thermodynamic Calculation and Micromagnetic Simulation

“…The intermetallic compounds are treated as stoichiometric compounds, including the binary systems of B–Nd, B–Dy, B–Fe, Dy–Nd, Dy–Fe, and Fe–Nd, and the ternary systems of Nd–Fe–B, Dy–Fe–B, Nd–Dy–Fe, and Nd–Dy–B, which were described using the sublattice model [ 28 ]. Among these systems, the thermodynamic basements of B–Nd [ 29 ], B–Dy [ 30 ], B–Fe [ 31 ], Dy–Fe [ 32 ], Fe–Nd [ 33 ], and Nd–Fe–B [ 29 , 34 ] were reported in several studies with critical thermodynamic data; thus, the thermodynamic optimization process of the Nd–Dy–Fe–B system was launched on the direct basis of these data. The optimized results of the model parameters are listed in Table 1 .…”

“…The intermetallic compounds are treated as stoichiometric compounds, including the binary systems of B-Nd, B-Dy, B-Fe, Dy-Nd, Dy-Fe, and Fe-Nd, and the ternary systems of Nd-Fe-B, Dy-Fe-B, Nd-Dy-Fe, and Nd-Dy-B, which were described using the sublattice model [28]. Among these systems, the thermodynamic basements of B-Nd [29], B-Dy [30], B-Fe [31], Dy-Fe [32], Fe-Nd [33], and Nd-Fe-B [29,34] were reported in several studies with critical thermodynamic data; thus, the thermodynamic optimization process of the Nd-Dy-Fe-B system was launched on the direct basis of these data. The optimized results of the model parameters are listed in Using the Gibbs energy functions obtained from the above approach, the thermodynamic calculations containing the Gibbs energy-minimizing routine were conducted under various conditions using the open-source thermodynamic software packages of Open CALPHAD [35].…”

Development of a prototype thermodynamic database for Nd-Fe-B permanent magnets

“…Zhou et al [ 84 ] have considered some metastable compounds. More recently Chen et al [ 85 ] reassessed the B-Nd binary system. One of the major problems pointed out in these assessments is the uncertainty of the phase equilibria between liquid and borides in the B-Nd binary system assessed by Hallemans et al [ 56 ].…”

“…Phase names, constituents and sublattices, Structure type, and Pearson symbols included in this database where "Va" denotes vacancy and Phases with "*" are not unified.Nd system on the bases of theoretical calculations. For expansion to higher-order systems, and to improve the descriptions of the Gibbs energy, the Gibbs energy functions adopted in the present work are based on the assessment of Hallemans et al In the previous assessments[56,[82][83][84][85][86], there is one significant uncertainty, which is the Gibbs energy of the Nd 2 Fe 14 B phase because the heat capacity of the compound is not Fe 14 B. According to their experimental results, it has a T C and the magnetic moment are 585.3 K and 2.04, respectively.…”

Solidification Behavior of Dy-Tb-Fe Alloys through Experimental Study and Thermodynamic Calculation

“…Using thermodynamic calculations, the Scheil–Gulliver model can be employed to simulate the non-equilibrium solidification process of as-cast alloys [ 19 ]. In our previous work, the RE-Fe (RE = Pr, Nd, Sm, Gd, Dy, Tb, Ho, Tm, Lu, Y) [ 20 , 21 , 22 , 23 , 24 ], RE-B (RE = La, Ce, Pr, Nd, Sm, Gd, Dy, Tb, Ho, Tm, Lu, Y) [ 25 , 26 , 27 ], and RE 1 -RE 2 binary systems [ 28 ] were calculated, and then thermodynamic calculations of the RE 1 -RE 2 -Fe (e.g., La-Ce-Fe and Ce-Nd-Fe [ 29 ], La-Pr-Fe and Ce-Pr-Fe [ 30 ]) ternary systems and the Nd-Fe-B ternary system [ 31 ] were performed. Furthermore, the development of a thermodynamic database of Nd-Dy-Tb-Fe-B magnets is in progress in our group.…”