Evolution and thermal stability of Ni{sub 3}V and Ni{sub 2}V phases in a Ni-29 at. pct V alloy
- Bhabba Atomic Research Centre, Mumbai (India). Materials Science Div.
Eutectoid decomposition of the disordered fcc Ni-V solid solution in the composition range of 25 to 33.3 at. pct V gives rise to a mixture of the ordered Ni{sub 3}V and Ni{sub 2}V phases. In the present work, the evolution and thermal stability of these phases were studied in a Ni-29 at. pct V alloy. Solution-treated and water-quenched specimens, when aged at 850 C, were found to exhibit two types of microstructure. In the first, the Ni{sub 2}V phase precipitated in a lamellar Ni{sub 3}V matrix where a pair of conjugate lamellae corresponded to two variants of the Ni{sub 3}V phase. In the second morphology, the Ni{sub 2}V phase precipitated within a Ni{sub 3}V matrix comprising a single variant of the Ni{sub 3}V phase. The Ni{sub 2}V phase was observed to precipitate in a plate-shaped morphology, exhibiting {l_brace}120{r_brace}{sub fcc}-type, habit planes. The precipitation of the Ni{sub 2}V plates in the Ni{sub 3}V lamellae resulted in zigzag interfaces between adjacent Ni{sub 3}V domains. Both the microstructures were found to be thermally quite stable and did not coarsen appreciably on prolonged aging. However, the prolonged aging caused the renucleation of the Ni{sub 3}V and the Ni{sub 2}V phases in the vicinity of the grain boundaries in a manner similar to recrystallization. The stability of the aged microstructure could be attributed to the nature of the interfaces between different domains of the Ni{sub 3}V and Ni{sub 2}V phases.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 634563
- Journal Information:
- Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 7 Vol. 29; ISSN MMTAEB; ISSN 1073-5623
- Country of Publication:
- United States
- Language:
- English
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