Thermodynamic re-assessment of the Fe-Dy and Fe-Tb binary systems

Electrochemical Formation of Dy–Fe Alloys in Molten LiF–CaF2–DyF3

“…8 shows that this sample consists of a mixture of DyFe 3 and Dy 2 Fe 17 ; that is, the XRD pattern is in fact a mixture of the patterns of these two alloys and does not correspond with the diffraction pattern of Dy 6 Fe 23 . In the paper by Rong et al 39 on CALPHAD for the Dy-Fe binary system, the calculated phase diagrams by Landin et al 40 and Su et al 41 showed the instability of Dy 6 Fe 23 at low temperatures. In summary, in the case of sample C, Dy 6 Fe 23 was formed during the electrolysis at 1123 K; however, this phase possibly phase-separated into DyFe 3 and Dy 2 Fe 17 during the cooling to room temperature after the electrolysis.…”

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].…”

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

“…The thermodynamic database of Dy-Fe and Tb-Fe systems in the high-temperature range (above 800 K) was established by Landin et al [ 32 ], but the contribution of magnetism to the Gibbs energy and experimental heat capacity of all intermetallic compounds were not taken into account. Rong et al [ 22 ] optimized the Dy-Fe and Tb-Fe systems using the CALPHAD method considering the magnetic contribution and experimental heat capacity of the intermetallic compounds. The calculation results including phase relationship and thermodynamic properties are in good agreement with the experimental results.…”

“…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.…”