Experimental investigation and thermodynamic modeling of the Ni–Pr system

Huang, Mianliang; Lograsso, Thomas A.

doi:10.1016/j.jallcom.2004.11.039

Cited by 17 publications

(10 citation statements)

References 18 publications

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“…Approximately 20 ternary intermetallic compounds have been reported [18] for the Pr-Ni-Si system, in accordance with what was reported for Ce-Ni-Si [19], and Nd-Ni-Si [20]. One of those is the compound Pr 7 Ni 2 Si 5 .…”

Section: Growth Of Pr 7 Ni 2 Sisupporting

confidence: 84%

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Differential thermal analysis and solution growth of intermetallic compounds

Janssen

Angst

Dennis

et al. 2005

Journal of Crystal Growth

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To obtain single crystals by solution growth, an exposed primary solidification surface in the appropriate, but often unknown, equilibrium alloy phase diagram is required. Furthermore, an appropriate crucible material is needed, necessary to hold the molten alloy during growth, without being attacked by it. Recently, we have used the comparison of realistic simulations with experimental differential thermal analysis (DTA) curves to address both these problems. We have found: (1) complex DTA curves can be interpreted to determine an appropriate heat treatment and starting composition for solution growth, without having to determine the underlying phase diagrams in detail. (2) DTA can facilitate identification of appropriate crucible materials. DTA can thus be used to make the procedure to obtain single crystals of a desired phase by solution growth more efficient. We will use some of the systems for which we have recently obtained single-crystalline samples using the combination of DTA and solution growth as examples. These systems are TbAl, Pr 7 Ni 2 Si 5 , and YMn 4 Al 8 .

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Section: Growth Of Pr 7 Ni 2 Sisupporting

confidence: 84%

“…However, we have often observed that binary phase diagrams with rare-earth components need revision (see e.g. [18]), and the Tb-Al binary phase diagram was already known to be uncertain [16,17].…”

Section: Article In Pressmentioning

confidence: 99%

Differential thermal analysis and solution growth of intermetallic compounds

Janssen

Angst

Dennis

et al. 2005

Journal of Crystal Growth

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“…Fig. 1, five intermetallic compounds, namely, PrNi, PrNi 2 , PrNi 3 , Pr 2 Ni 7 , PrNi 5 , and a liquid alloy exist in the Pr-Ni system at 973 K. 17 Open-circuit potentiometry.-The deposition potential of Pr metal was determined to be 0.23 V by open-circuit potentiometry for a Mo electrode after galvanostatic electrolysis at -0.25 A cm −2 for 20 s in molten NaCl-KCl-PrCl 3 (0.50 mol%) at 973 K; this procedure is the same as that employed in our previous studies. 10,11 Subsequently, open-circuit potentiometry was carried out for the Ni plate electrode in order to examine the potentials of Pr-Ni alloy formation.…”

Section: Resultsmentioning

confidence: 97%

Electrochemical Formation of Pr–Ni Alloys in LiF–CaF₂–PrF₃and NaCl–KCl–PrCl₃Melts

Yasuda

Kondo

Hagiwara

2014

J. Electrochem. Soc.

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For the establishment of a process for the electrochemical recovery of rare earth elements from used magnet scraps, the electrochemical formation of Pr-Ni alloys in molten LiF-CaF 2 -PrF 3 and NaCl-KCl-PrCl 3 salts at 1123 K and 973 K, respectively, was investigated.Cyclic voltammetry and open-circuit potentiometry indicated the formation of several phases of Pr-Ni alloys. Alloy samples were prepared by one-or two-step potentiostatic electrolysis using a Ni plate electrode at various potentials. Scanning electron microscopy observations and X-ray diffraction measurements confirmed the formation of PrNi 2 , PrNi 3 , Pr 2 Ni 7 , and PrNi 5 . The formation potential for each Pr-Ni alloy phase was determined from experimental results. In addition, the optimum electrolysis conditions for the separation of Nd, Dy, and Pr are discussed.Rare earth (RE) metals have several superior characters such as electric, magnetic, and fluorescence properties and are therefore indispensable as industrial materials throughout the world. Among the many applications of RE metals, the use of neodymium-ironboron (Nd-Fe-B) magnets-the so-called neodymium permanent magnets-has been remarkably increasing recently. Neodymium permanent magnets composed of a Nd 2 Fe 14 B main phase have several advantages such as superior magnetic properties and high mechanical strength, and are used for voice coil motors in hard disk drives (HDDs), magnetic resonance imaging (MRI), speakers/vibrators in cell phones, and motors in electric vehicles (EVs) and hybrid electric vehicles (HEVs). Since praseodymium (Pr) and Nd have similar chemical properties, they are found in nature in the same ores and their separation is difficult. Thus, in some applications including permanent magnets, a Nd-Pr alloy called didymium (Di) is sometimes utilized. On the other hand, Nd-Fe-B magnets have the drawback of a relatively low Curie temperature of ∼583 K. In order to maintain its superior coercive force even at high temperatures (above 473 K), where high-performance motors in EVs and HEVs operate, dysprosium (Dy) is necessary as an additive.One of the concerns pertaining to RE magnets is the uneven distribution of RE resources: in 2011, China had 50% of the proven RE reserves and produced over 97% of the global RE supply. 1 In 2010-2012, the price of REs increased sharply, causing supply problems for the magnets. While the present RE production capacity satisfies the demand and their price has lowered, there remains the potential for RE shortage in the future.On the basis of these supply circumstances, it can be concluded that the recycling or waste management of Nd-Fe-B magnet scraps is currently an urgent task. The conventional wet processes for RE recycling from Nd-Fe-B magnet scraps have several disadvantages such as their multistep and complicated processes, high environmental loads, and large energy consumption. As new recycling methods, pyrometallurgical processes such as chemical vapor transport, 2 selective reduction, 3 molten salt electrolysis, 4 and ionic liquid e...

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“…The small peak in the curve for NdNi is associated with the eutectic reaction between NdNi and NdNi 2 and the second large peak is for the melting of NdNi. study in the Ni-Pr system [22]. Fig.…”

Section: Resultsmentioning

confidence: 99%