Microstructure and Oxidation Resistance of Mechanically Alloyed and Sintered Ni-Nb and Ni-Nb-Ta Alloys

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The present work reports on the microstructure and oxidation resistance of Ni-25Nb, Ni-20Nb-5Ta and Ni-15Nb-10Ta alloys produced by high-energy ball milling and subsequent sintering. The sintered samples were characterized by optical microscopy, scanning electron microscopy, X-ray diffraction, energy dispersive spectrometry, and static oxidation tests. Homogeneous microstructures of the binary and ternary alloys indicated the major presence of the β-Ni3Nb compound as matrix, which dissolved large amounts of tantalum. Consequently, the β-Ni3Nb peaks moved toward the direction of smaller diffraction angles. Iron contamination lower than 6.7 at.-% was detected by EDS analysis, which were picked-up during the previous ball milling process. After the static oxidation tests (1100°C for 4 h) the sintered Ni-25Nb, Ni-20Nb-5Ta and Ni-15Nb-10Ta alloys presented mass gains of 31.5%, 30.5% and 28.8%, respectively. Despite the higher densification of the Ni-15Nb-10Ta alloy, the results suggested that the tantalum addition contributed to improve the oxidation resistance of the β-Ni3Nb compound.

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Periodical:

Edited by:

Aloisio Nelmo Klein, Uílame Umbelino Gomes, Nério Vicente Jr. and Dr. Henning Zoz

Pages:

19-24

Citation:

L. M. Ferreira et al., "Microstructure and Oxidation Resistance of Mechanically Alloyed and Sintered Ni-Nb and Ni-Nb-Ta Alloys", Materials Science Forum, Vol. 899, pp. 19-24, 2017

Online since:

July 2017

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$38.00

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[1] C. Qiu, X. Wu, J. Mei, P. Andrews, W. Voice: Journal of Alloys and Compounds Vol. 578 (2013), p.454.

[2] C.A. Huang, T.H. Wang, W.C. Han, C.H. Lee: Materials Chemistry and Physics Vol. 104 (2–3) (2007), p.293.

[3] N. Matougui, D. Piot, M.L. Fares, F. Montheillet, S.L. Semiatin: Materials Science and Engineering A 586 (2013), p.350.

[4] M. Xie, R. Helmink, S. Tin: Journal of Alloys and Compounds Vol. 562 (2013), p.11.

[5] T. Tabaru, S. Hanada: Intermetallics Vol. 6 (7–8) (1998), p.735.

[6] G. Ghosh, G.B. Olson: Acta Materialia Vol. 55 (10) (2007), p.3281.

[7] A. Genç, M.L. Öveçoğlu, M. Baydoğan, S. Turan: Materials & Design Vol. 42 (2012), p.495.

[8] A.C. Ferraretto, E.C.T. Ramos, A.S. Ramos: Materials Science Forum Vol. 717 (2012), p.222.

[9] JCPDS: International Centre for Diffraction Date, Powder Diffraction File (Inorganic Phases) two volumes, first ed., Swarthmore, (1988).

[10] W. Kraus, G. Nolze: Journal of Applied Crystallography Vol. 29 (1996), p.301.

[11] F.H.C. Freitas: Avaliação das relações de fases do sistema ternário na região rica em Ni. Tese (Dissertação em Ciências – Materiais Metálicos, Cerâmicos e Poliméricos). Lorena: Universidade de São Paulo; (2011).

DOI: https://doi.org/10.11606/d.97.2011.tde-22082013-170741