Experimental study and thermodynamic calculation of the Mn-Dy and Mn-Ho binary systems. (September 2019)

• Record Type: Journal Article
• Authors: Wang, J.; Qian, M.; Yang, K.C.; Wen, B.; Lu, Z.; Rong, M.H.; Rao, G.H.; Zhou, H.Y.
• Is Part Of: Calphad. Volume 66(2019)
• Publication Date: 2019-09
• Subjects: Mn-Dy -- Mn-Ho -- Phase equilibria -- Thermal analysis -- CALPHAD; Phase diagrams -- Data processing -- Periodicals; Thermochemistry -- Data processing -- Periodicals; Diagrammes de phases -- Informatique -- Périodiques; Thermochimie -- Informatique -- Périodiques; Thermodynamica; Electronic journals; 541.363
• DOI: 10.1016/j.calphad.2019.101635
• Languages: English
• ISSNs: 0364-5916

Abstract

Abstract: In this work, twenty-four Mn-Dy and Mn-Ho alloys were investigated experimentally using the differential thermal analysis (DTA), scanning electron microscopy (SEM) and electronic probe microanalysis (EPMA) to study phase equilibria of the Mn-Dy and Mn-Ho binary systems. The temperatures of some invariant reactions and liquidus in the Mn-Dy and Mn-Ho binary systems were determined. Based on the experimental results obtained in the present work and the critical evaluation of the experimental data reported in the literature, the Mn-Dy and Mn-Ho binary systems were calculated using the CALPHAD method. In the thermodynamic calculation, the solution phases including liquid, α(Mn), β(Mn), γ(Mn), δ(Mn), α(Dy), β(Dy), α(Ho) and β(Ho), are treated as the substitutional solution model with the Redlich-Kister formula. The intermetallic compounds, Mn2 Dy, Mn12 Dy, Mn23 Dy6, Mn2 Ho, Mn12 Ho and Mn23 Ho6, are modeled as the stoichiometric compounds. Self-consistent thermodynamic parameters were obtained finally to describe the Gibbs energies of various stable phases in the Mn-Dy and Mn-Ho binary systems. The calculated results reproduce well the phase equilibria and thermodynamic properties. Highlights: The invariant reactions and liquidus were determined by thermal analysis. The Mn-Dy and Mn-Ho binary systems were assessed using CALPHAD method. Self-consistent thermodynamic parameters of these two binary systems were obtained. The calculation results agree well with phase equilibria and thermodynamic data.