Oxidation Behavior of Oxide Dispersion-Strengthened W–Ni Alloys
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Oxidation behavior (at 1000 °C for 10 h) of 1.0 wt% oxide dispersion-strengthened (nano-Y2O3, Al2O3, La2O3 dispersed) mechanically alloyed (10 h) and sintered (1400 °C, 1500 °C, 2 h) W–Ni alloys has been investigated. Oxidation significantly constrains the application window of W and therefore needs to be counteracted by suitable alloying and dispersion. W–Ni–Y2O3 alloy possesses excellent oxidation resistance at the high sintering temperatures. Moreover, W–Ni–Al2O3 sintered at 1400 °C exhibited no spallation or blistering after 10 h of oxidation. The enhanced oxidation resistance of W–Ni–Y2O3 alloy is attributed to superior densification, oxide-scale adhesion with the matrix phase, reduced volatilization of WO3 owing to NiWO4 and enhanced concentration of Y ions enriched with oxide. The investigation will provide a strategy to fabricate oxidation-resistant alloys by oxide dispersion for high-temperature applications.
KeywordsODS W alloy Free energy Oxidation Residual stress
Financial assistance from TEQIP II NIT Rourkela for the project work is acknowledged. The support of FIST-DST for XRD, residual stress study is also acknowledged.
- 2.E. Lassner, and W. D. Schubert, Tungsten Properties, Chemistry, Technology of the Element, Alloys, and Chemical Compounds, (Kluwer Academic, New York, 1999).Google Scholar
- 4.J. R. Davis, ASM Specialty Handbook: Heat-Resistant Materials, (ASM International, Cleveland, 1999).Google Scholar
- 18.B. Verlinden, J. Driver, I. Samajdar, R. D. Doherty, and R. W. Cahn, Thermo-Mechanical Processing of Metallic Materials, Series ed., Pergamon Materials Series, (Elsevier, Amsterdam, 2007), p. 187.Google Scholar
- 19.H. Wawra, Zeitschrift für Metallkunde69, 518 (1978).Google Scholar
- 30.V. A. Levitskii, V. N. Chentsov, Y. Yaskolis, and Y. G. Golovanova, Russian Journal of Physical Chemistry46, 151 (1972).Google Scholar