Heat Treatment and Oxidation Characteristics of Nb-20Mo-15Si-5B-20(Cr,Ti) Alloys from 700 to 1400°C


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Nb-20Mo-15Si-5B-20(Cr,Ti) alloys have been subjected to annealing treatment for 2 hours in a range of temperatures from 700 to 1400oC and quenched in water to perform the microstructural characterization for these two new alloys. As cast structure consists of a solid solution phase, , and silicides (Nb5Si3) in both alloys but Cr alloy also contains NbCr2 and Nb3Si phases. Heating to higher temperature introduces Ti silicides in the microstructure for Ti alloy. The oxidation in air has been conducted on these alloys in the same temperature range for 24 hours. Weight gain per unit area as a function of temperature provides the oxidation curves while characterization techniques using SEM, EDS on SEM, x-ray mapping, and XRD has yielded the analyses of the oxide scale. The scale consists of various oxides of Nb, Mo, Cr, Si, and Ti. Cr alloy appears to offer higher oxidation resistance in the selected range of oxidation temperatures.



Materials Science Forum (Volumes 638-642)

Main Theme:

Edited by:

T. Chandra, N. Wanderka, W. Reimers , M. Ionescu






S. Natividad et al., "Heat Treatment and Oxidation Characteristics of Nb-20Mo-15Si-5B-20(Cr,Ti) Alloys from 700 to 1400°C", Materials Science Forum, Vols. 638-642, pp. 2351-2356, 2010

Online since:

January 2010




[1] Maria D. Moricca, S.K. Varma: Journal of Metals, Vol. 60(7) (2008), p.66.

[2] Benedict Portillo, P. Kakarlapudi, S.K. Varma, Journal of Metals: Vol. 59(6) (2007), p.46.

[3] P. Kakarlapudi, S.K. Varma: in: Processing and Fabrication of Advanced Materials XV, ASM Publication (2006), p.131.

[4] PANDATTM, Phase Diagram Calculation Software for Multicomponent Systems, Computherm LLC, Madison, WI, 53719, (2007).

[5] Metals Handbook, ninth edition, vol. 3, ASM International, Materials Park, OH, 1999, p.3. 5.

[6] Julieta Ventura, Benedict Portillo, S.K. Varma: Journal of Alloys and Compounds, in press.

[7] K. Yanagihara, K. Pryzbylski, T. Maruyama: Oxidation of Metals, Vol. 47 (1997), p.277.

[8] M.K. Meyer, A.J. Thom, and M. Akinc: Intermetallics, Vol. 7 (1999), p.153.

[9] M.G. Mendiratta, T.A. Parthasarthy, D.M. Dimiduk: Intermetallics, Vol. 10 (2002), p.225.

[10] K. Ito, T. Murakami, K. Adachi, M. Yamaguchi: Intermetallics, Vol. 11 (2003), p.763.

[11] F.H. Stott, G.C. Wood, J. Stringer: Oxidation of Metals, Vol. 44 (1995), p.113.

[12] High Temperature Alloys, Kirk-Othmer Encyclopedia of Chemical Technology, 5th edition, vol. 13.

[13] ASM Metals Handbookm formerly ninth edition, vol. 13, ASM International, Materials Park, OH, 1990, p.98.

[14] T. Murakami, S. Sasaki, K. Ichikawa, A. Kitahara: Intermetallics, Vol. 9 (2001), p.629.

[15] J. Geng, P. Tsakiropoulos: Intermetallics, Vol. 15 (2007), p.382.

[16] K.S. Chan: Metallurgical and Materials Transcations A, Vol. 13 (2003), p.589.

[17] J. Geng, P. Tsakiropoulos, G. Shao: Materials Science and Engineering A, Vol. 441 (2006), p.26.

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