Oxidation Behavior of Ta-W Alloy

Abstract:

The oxidation behaviors of tantalum-tungsten alloy with 10-20% W was investigated between temperature range of 700 to 900 °C exposed in air. The kinetics of Ta-W alloy was determined by TG-DTA, the characteristics of oxides were analyzed by SEM, EDS and XRD. The oxidation tests revealed that the alloys obeyed parabolic kinetic in the initial stage, then translated in linear law. The addition of W has a good effect on the oxidation resistance of Ta-W alloys at experimental temperature. Solid solution of Ta₂O₅ form in case of oxidation product of Ta-10W, Ta-15W alloys, while the complex oxide Ta₂₂W₄O₆₇ form after Ta-20W alloy oxidized. The formation of solid solution and complex oxide impeded the volatilization. The compact oxide film protects the penetration of oxygen in the initial oxidation stage. The large compressive stresses and mismatch of the coefficient of thermal expansion between oxide scale and matrix alloys make the oxides layer be broken, which cause kinetic of oxidization obeying linear law.

• Periodical: Materials Science Forum (Volume 993)
• Pages: 299-306
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.993.299
• Online since: May 2020
• Authors: Jia Xin Li, Yu Hong Chen*, Zhang Jun Bai, Shuai Du, Lan Er Wu
• Keywords: Alloy, Oxidation Behavior, Solid Solution, Tantalum, Tungsten

References

[1] S. Chen, G. T. Gray. Constitutive behavior of tantalum and tantalum-tungsten alloys. Metallurgical and Materials Transactions A. 27A (1996) 2994-3006.

DOI: 10.1007/bf02663849

[2] Z. Lin, E. J. Lavernia, F.A .Mohamed. High-temperature deformation in a Ta–W alloy. Acta Materialia. 47(4) (1999) 1181-1194.

DOI: 10.1016/s1359-6454(98)00434-0

[3] M. Dias, F. Guerreiro, J. B. Correia et al. Consolidation of W–Ta composites: Hot isostatic pressing and spark and pulse plasma sintering. Fusion Engineering and Design. 98 (2015) 1950-1955.

DOI: 10.1016/j.fusengdes.2015.06.178

[4] Z. H. Dongn, X. Peng, F. H. Wang, Oxidation of a ZrB2 coating fabricated on Ta–W alloy by electrophoretic deposition and laser melting. Materials Letters. 148 (2015) 76-78.

DOI: 10.1016/j.matlet.2015.02.075

[5] P. Kofstad, J. Krudtaa. High Temperature Metallurgical Microscope Studies of the Initial Oxidation of Tantalum. Journal of the less-common metal. 5 (1963) 477-492.

DOI: 10.1016/0022-5088(63)90061-4

[6] V. B. Voitovich, V. A. Lavrenko, V. M. Adejev, and E. I. Golovko. High-Temperature Oxidation of Tantalum of Different Purity. Oxidation of Metals. 43 (1995) Nos. 5/6.

DOI: 10.1007/bf01046896

[7] O. Kubaschewski, B. E. Hopkins. Oxidation mechanisms of Niobiums, Tantalum, Molybdenum and Tungsten. Journal of the less-common metal. 2 (1960) 172-180.

DOI: 10.1016/0022-5088(60)90012-6

[8] Youngsoo Park. Darryl. P. Butt, Composition Dependence of the Kinetics and Mechanisms of Thermal Oxidation of Titanium-Tantalum Alloys. Oxidation of Metals. 51 Nos.5/6 (1999) 383-402.

[9] Li Tiefan, Li Meishuang. The Measurement of the critical cracking stresses of the oxide scale during the oxidation of tantalum. Journal of the Chinese society of corrosion and protection, 10 (1990) 9-13.

[10] J. Stringer. The oxidation of tantalum at high temperatures: geometrical effects. Journal of the Less-Common Metals.16 (1968) 55-64.

DOI: 10.1016/0022-5088(68)90156-2

[11] Ramesh Chandrasekharan, Inkyu Park, R. I. Masel, Mark A. Shannon. Thermal oxidation of tantalum films at various oxidation states from 300 to 700℃. Journal of Applied Physics, 98 (2005) 114908.

DOI: 10.1063/1.2139834

[12] P. Kofstad. High Temperature Oxidation of Metals, New York, Wiley. (1966).

[13] F. J. Harvery. High temperature oxidation of tungsten wires in O2-Ar mixtures Metallurgical transactions. 4 (1973) 1513-1517.

DOI: 10.1007/bf02668002

[14] Li Hanguang, Peng Zhihui, Investigation on Oxidizing Kinetics of W Powder (in Chinese). Rear metal. 123(12) (1995) 1-6.

[15] Nilsson C, Habainy J. Oxidation of Pure Tungsten in the Temperature Interval 400°C to 900°C[J]. Diploma work. (2013).

[16] Anna Warren, Anders Nylund and Ingemar Olefjord. Oxidation of Tungsten and Tungsten Carbide in Dry and Humid Atmospheres. J. of Refractory Metals & Hard Materials. 14 (1996) 345-353.

DOI: 10.1016/s0263-4368(96)00027-3

[17] C. T. Liu, R. W. Carpenter, H. Inouye. Oxygen Distribution in Internally-Oxidized Ta-8 Pct W-2 Pct Hf Alloy. Metallurgical Transaction A. 6A (1975) 419-421.

DOI: 10.1007/bf02667300

[18] J. R. DiStefano and J. W. Hendricks. Oxidation Rates of Niobium and Tantalum Alloys at Low Pressures. Oxidation of Metals. 41 Nos.5/6 (1994) 365-376.

DOI: 10.1007/bf01113371

[19] R.S. Roth, J. L.Waring. Effect of oxide additions on the polymorphism of tantalum pentoxide III. Stabilization of the low temperature structure type, J. J. Res. Natl. Bur. Stand A: Phys Chem A. 74(4) (1970).

DOI: 10.6028/jres.074a.038

[20] S. Schmid, R. L. Withers, J. G. Thompson. The incommensurately modulated (1−x) Ta2O5· xWO3, 0≤ x≤ 0.267 solid solution, J. J. Solid State Chem. 99(2) (1992) 226-242.

DOI: 10.1016/0022-4596(92)90310-r

[21] T. Li, High temperature oxidation and hot corrosion of metals, Beijing: Chemical Industry Press, 2003. (in Chinese).