Homolová V, Čiripová L, Zobač O, Zemanová A, Falat L. Experimental Investigation of Phase Equilibria of the Ho-Ir-O Ternary System at 1073 K.
MATERIALS (BASEL, SWITZERLAND) 2023;
16:5406. [PMID:
37570110 PMCID:
PMC10419622 DOI:
10.3390/ma16155406]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/26/2023] [Accepted: 07/29/2023] [Indexed: 08/13/2023]
Abstract
An experimental study of the phase equilibria of the Ho-rich part of the Ho-Ir-O ternary system at 1073 K by means of x-ray diffraction, differential scanning calorimetry, and scanning electron microscopy has been carried out. Ho-hcp and four binary compounds, namely Ho3Ir, Ho5Ir2, Ho5Ir3, and Ho2O3, were identified in the Ho-Ir-O model alloys after long-term annealing (350-1220 h). No solubility of iridium in Ho2O3 oxide and Ho-hcp was observed. No ternary phase was found. Based on the experimental results, an isothermal section of the Ho-rich part of the Ho-Ir-O system at 1073 K was constructed. In addition, the microstructure of as-cast alloys was studied. An irregular eutectic consisting of faceted Ho-phase in Ho3Ir phase was observed in the alloys with Ho-hcp + Ho3Ir + Ho2O3 phase composition, and the temperature of the eutectic reaction Ho-hcp + Ho3Ir ↔ liquid was determined.
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