Thermodynamic Calculations and Parameter Variations for Improving the Extraction Efficiency of Dy in Ternary Alloy System

• Published in: Metals and materials international 2021, 27(3), , pp.538-544
• Main Authors: Nam, Sun-Woo, Park, Sang-Min, Kim, Do-Hyang, Kim, Taek-Soo
• Format: Article
• Language: English
• Subjects: Alloy systems; Boron compounds; Characterization and Evaluation of Materials; Chemistry and Materials Science; Dysprosium base alloys; Efficiency; Engineering Thermodynamics; Heat and Mass Transfer; Intermetallic compounds; Iron; Liquid metal extraction; Machines; Magnesium; Magnetic Materials; Magnetism; Manufacturing; Materials Science; Mathematical analysis; Metallic Materials; Process parameters; Processes; Rapid solidification; Reaction time; Solid Mechanics; Ternary alloys; 재료공학
• ISSN: 1598-9623; 2005-4149
• DOI: 10.1007/s12540-019-00605-8

The extraction behavior of dysprosium (Dy) in a rapidly solidified Dy–Fe–B alloy system consisting of Dy 2 Fe 14 B and Dy 6 Fe 23 phases was investigated using the liquid metal extraction (LME) process. Liquid magnesium (Mg) was selected as the solvent metal in LME because it forms intermetallic compounds with Dy but not with iron (Fe) and boron (B) in this process. The diffusion behavior of Dy was estimated through thermodynamic calculations and subsequently confirmed by process parameters such as temperature and reaction time. As the temperature increases, the extraction rate increases and the maximum extraction efficiency is about 74% Dy for 1 h at 1000 °C. As the reaction time increases, we achieved the maximum extraction efficiency of 95% Dy after 24 h at 900 °C. The factor affecting Dy extraction ratio up to 6 h is Dy 6 Fe 23 phase, after which the extraction mainly occurs in Dy 2 Fe 14 B phase. Furthermore, the diffusion behavior is described in detail with analysis based on microstructural and compositional properties. The effects of process parameters on extraction rate are also discussed. Graphic Abstract