Experimental Investigation of Intermetallics and Phase Equilibria in the Hf-Mo-Ni System at 1100 °C and 950 °C

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Physical metallurgy and materials science, 2021-03, Vol.52 (3), p.1059-1076
• Main Authors: Shi, Jiejie, Guo, Cuiping, Li, Changrong, Du, Zhenmin
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Intermetallic compounds; Materials Science; Metallic Materials; Molybdenum; Nanotechnology; Nickel; Original Research Article; Phase equilibria; Phase stability; Plasma sintering; Solubility; Spark plasma sintering; Structural Materials; Surfaces and Interfaces; Thin Films
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-020-06120-5

The diffusion triples of the Hf-Mo-Ni system were successfully fabricated by spark plasma sintering (SPS). The phase stability of intermetallics and phase equilibria relations of the Hf-Mo-Ni system were studied by diffusion triples and equilibrated alloys. A new intermetallic compound τ with Hf 2 Rh structure was detected, the composition of which is close to Hf:(Ni + Mo) = 2:1. NiHf 3 with BRe 3 structure was proven to be stable at 1100 °C and 950 °C in the Hf-Ni and Hf-Mo-Ni systems. The Mo solubility in the Ni 7 Hf 2 phase was 4.9 at. pct at 1100 °C and 4.6 at. pct at 950 °C. The solubility of Mo in other compounds in the Hf-Ni system could be neglected. The solubility of Ni in α Mo 2 Hf was 5.4 at. pct at 1100 °C and 3.8 at. pct at 950 °C. An invariant reaction α NiHf + bcc(Mo) ↔ Ni 11 Hf 9 + α Mo 2 Hf should occur between 950 °C and 1100 °C according to phase relations among α NiHf, bcc(Mo), Ni 11 Hf 9 , and α Mo 2 Hf at 950 °C and 1100 °C.