Effects of rare earth yttrium on microstructure and properties of Ni–16Mo–7Cr–4Fe nickel-based superalloy

Journal Article · Mon Sep 15 04:00:00 EDT 2014 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2014.06.016· OSTI ID:22403546

Li, X. L. ^[1]; Zhou, X. T.; Zou, Y.; Li, Z. J. ^[1]; Li, A. G. ^[2]; Yu, X. H. ^[1]

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1. Shanghai Institute of Applied Physics, China Academy of Sciences, 2019 Jialuo Road, Shanghai 201800 (China)
2. Shanghai Synchrotron Radiation Facility (SSRF), Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 239 Zhangheng Road, Shanghai 201204 (China)

Effects of rare earth yttrium on microstructure of Ni–16Mo–7Cr–4Fe alloy were examined by optical microscopy, scanning electron microscopy, transmission electron microscopy and X-ray fluorescence. M{sub 6}C phase was observed in the alloys with and without yttrium addition, and Ni{sub 17}Y{sub 2} phase existed in the alloys containing 0.05–0.43 wt.% yttrium simultaneously. The amount of Ni{sub 17}Y{sub 2} phase increased as yttrium concentration increased. When the concentration of yttrium increased to 0.43 wt.%, some multi-precipitated phase regions appeared in the form of large amount of coarse Ni{sub 3}Y phase surrounded by M{sub 6}C phase and γ phase in the alloy. Influences of rare earth yttrium on high temperature static oxidation and mechanical properties of Ni–16Mo–7Cr–4Fe alloy were also investigated. The alloy containing 0.05 wt.% yttrium showed the best oxidation resistance and mechanical properties simultaneously. The adequate concentration of yttrium at grain boundary and in the solid-solution (γ phase) and the adhesion enhancement of the outer oxidation scale to the substrate are key factors for the improvements in the mechanical properties and oxidation resistance respectively. - Highlights: • When the content of yttrium reaches to 0.43%, some multiphase regions appear. • When the content of yttrium reaches to 0.43%, some Ni{sub 17}Y{sub 2} chains appear. • The morphology of M{sub 6}C changes with increasing concentration of yttrium. • The Ni–16Mo–7Cr–4Fe alloy with 0.05% yttrium performs the best mechanical property. • The Ni–16Mo–7Cr–4Fe alloy with 0.05% yttrium performs the best oxidation resistance.

• OSTI ID: 22403546
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 95; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHROMIUM ALLOYS
CONCENTRATION RATIO
GRAIN BOUNDARIES
IRON ALLOYS
MECHANICAL PROPERTIES
MOLYBDENUM BASE ALLOYS
MORPHOLOGY
NICKEL
NICKEL ALLOYS
OPTICAL MICROSCOPY
OXIDATION
RARE EARTHS
SCANNING ELECTRON MICROSCOPY
SOLID SOLUTIONS
SUBSTRATES
TRANSMISSION ELECTRON MICROSCOPY
YTTRIUM
YTTRIUM ADDITIONS