Alloys of rare earth metals

Critical Systematic Evaluation and Thermodynamic Optimization of the Fe-RE System: RE = Gd, Tb, Dy, Ho, Er, Tm, Lu, and Y

“…Gd 2 Fe 17 ? Gd 6 Fe 23 is calculated at 0.281 X Gd in this study, which is slightly higher than the experimental value 0.28 X Gd from Savitskii, [46] while the previous assessments calculated at about 0.235 [39] and 0.210 X Gd . [40] The other invariant reaction compositions are all calculated within experimental error ranges.…”

“…An eutectic reaction between Gdrich phase and GdFe 2 was also reported at 0.72 mol fraction Gd (X Gd ) and 830 ± 7°C. Later, Savitskii [46] reported four intermetallic phases Gd 2 Fe 17 , GdFe 4 , GdFe 3 , and GdFe 2 where all showed peritectic melting behaviors. In the review by Kubaschewski, [42] the phase diagram of the Fe-Gd system was proposed based on the experimental results of Copeland et al [44] with the modification of peritectic melting of Gd 6 Fe 23 based on Savitskii et al [46] and Burov et al [48] Most recently, Atiq et al [49] investigated the phase transformations in the Fe-rich side (less than 0.32 X Gd ) which were determined by DTA and diffusion couple technique.…”

“…The solidus and liquidus temperatures were determined by TA and visually by optical pyrometry. Savitskii et al [45] investigated the phase diagram over the entire composition range with TA and equilibration technique followed by OM and XRD phase analyses and reported two compounds Gd 2 Fe 17 and GdFe 2 with peritectic melting. An eutectic reaction between Gdrich phase and GdFe 2 was also reported at 0.72 mol fraction Gd (X Gd ) and 830 ± 7°C.…”

“…The GdFe 9 and GdFe 4 reported by Copeland et al [44] and Savitskii [46] should be corresponding to Gd 2 Fe 17 and Gd 6 Fe 23 , respectively, according to more updated crystallographic information. The liquidus and solidus data by Savitskii et al, [45,46] Burov et al, [48] and Atiq et al [49] were mainly considered in the present modeling. The polymorphic transformation of the Gd 2 Fe 17 phase reported by Atiq et al [49] was not considered in the present study due to lack of information about the enthalpy of transformation.…”

“…1 along with the experimental data. [44][45][46][47][48][49][50] The invariant reactions are summarized in Table 3. The phase diagram of the Fe-Gd system was first investigated by Novy et al [50] Seven intermetallic phases, Gd 2 Fe 3 , GdFe 2 , GdFe 3 , Gd 2 Fe 7 , GdFe 4 , GdFe 5 and Gd 2-Fe 17 along with five invariant reactions were reported by differential thermal analysis (DTA) technique and optical pyrometry.…”