The Effect of Mn Addition on Oxidation Resistance of Ti-48Al Synthesized by Mechanical Alloying

Document Type : یادداشت پژوهشی

Authors

• Hadi Karimi ¹
• Ahmad Zare ¹
• Morteza Hadi ¹
• Mohsen Sadeghi ¹
• Ali Ghasemi ²

¹ Malek-e-Ashtar University of Technology

² MUT

10.22067/ma.v27i1.33240

Abstract

Titanium aluminide and its alloys have been utilized in automotive, aerospace and power industries because of their specific properties such as low density (~ 4 g/cm3), high melting temperature (~ 1460 °C) and excellent high-temperature strength. Ti-48Al intermetallic compound and its alloys with 1.5, 3 and 5 at.%Mn were produced with mechanical alloying of elemental powders for 50 hours. The process of mechanical alloying was carried out in a planetary ball mill machine with WC cups and balls under inert atmosphere of argon. To obtain bulk samples, the mechanically alloyed powders were cold pressed with the load of 40 ton and then heat treated at 1050 °C under argon atmosphere in an electrical furnace with quartz tubes. The X-ray diffraction analysis showed that the addition of manganese to Ti-48Al during mechanical alloying causes no formation of a new phase in titanium aluminide system. Scanning electron microscopy observations on the surface of sintered bulk samples revealed that boundaries between powder particles have been well formed at 1050 °C. The results of hardness tests showed that the addition of Mn up to 5 at.% increases the hardness value of Ti-48Al compound (~22.1 HRC) to ~ 40.7 HRC. Evaluation of oxidation behavior showed that oxidation resistance of Ti-48Al-5Mn alloy is slightly smaller (~0.015 g) than that of Ti-48Al. On the contrary to Ti-48Al-5Mn alloy, Ti-48Al compound had a steady-state oxidation behavior for oxidation periods longer than 14000 seconds. Scanning electron microscopy images and the results of energy dispersive spectroscopy showed that the lower oxidation resistance of Ti-48Al-5Mn compared to that of Ti-48Al is related to the formation of rutile at 900 °C on the oxidized surfaces of Ti-48Al-5Mn.

Keywords

• Amorphous
• Alloy Aluminide Titanium
• porosity
• Alumina
• Rutile

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References

1. Zhang, D.L, Yu, H.B. and Chen, Y.Y., "Mechanical properties and fracture behaviour of nanostructured and ultrafine structured TiAl alloys synthesised by mechanical milling of powders and hot isostatic pressing", Materials Science Forum ,Vol. 683 , pp. 149-1, (2011).
2. Yu, H.B., Zhang, D.L., Chena, Y.Y., Cao, P. and Gabbitas, B., "Synthesis of an ultrafine grained TiAl based alloy by subzero temperature milling and HIP, its microstructure and mechanical properties", Journal of Alloys and Compounds, Vol. 474, pp. 105-112, (2009).
3. Wenbin, F., Lianxi, H., Wenxiong, H., Erde, W. and Xiaoqing, L., "Microstructure and properties of a TiAl alloy prepared by mechanical milling and subsequent reactive sintering", Materials Science and Engineering A, Vol. 403, pp. 186–190, (2005).
4. Zhang, W.J., Chen, G.L., Appel, F., Nieh, T.G. and Deevi, S.C., "A preliminary study on the creep behavior ofTi–45Al–10Nb alloy", Materials Science and Engineering A, Vol. 315 (1-2), pp. 250-253, (2001).
5. Lu, X., He, X.B., Zhang, B., Qu, X.H., Zhanga, L., Guob, Z.X. and Tian, J.J., "High-temperature oxidation behavior of TiAl-based alloys fabricated by spark plasma sintering", Journal of Alloys and Compounds, Vol. 478, pp. 220-225,(2009).
6. Zhao, L.L., Li, G.Y., Zhang, L.Q., Lin, J.P., Song, X.P., Ye, F. and Chen, G.L., "Influence of Y addition on the long time oxidation behaviors of high Nb containing TiAl alloys at 900 ◦C" , Intermetallics, Vol. 18, pp. 1586-1596, (2010).
7. Lee D., "Effect of Cr, Nb, Mn, V, W and Si on High Temperature Oxidation of TiAl Alloys", Metals and Materials International, Vol. 11, pp.141-147, (2005).
8. Vojtech, D., Popela, T., Kubasek, J., Maixner, J. and Novak, P., "Comparison of Nb- and Ta-effectiveness for improvement of the cyclic oxidation resistance of TiAl-based intermetallics", Intermetallics, Vol. 19, pp. 493-501, (2011).
9. Shida, Y. and Anada, H., "The Influence of ternary element addition on the oxidation behaviour of TiAI intermetallics compound in high temperature air", Corrosion Science, Vol. 35, pp. 945-953, (1993).
10. Venketaraman, G., Jackson, A.G., Teal, K.R. and Froes F.H., "The influence of Nb addition on structure and properties of rapidly solidified intermetallics", Materials Science and Engineering, Vol. 98, pp. 257-263, (1988).
11. Suryanarayana, C., "Mechanical alloying and milling", Progress in Materials Science, New York, pp. 1-184, (2001).
12. Jnuhong, Z., Baiyun, H. and Yuehui, H., "Synthesis of amorphous Ti-Al alloys by mechanical alloying of elemental powders", Transactions of Nonferrous Metals society, Vol.12, pp. 610-614, (2002).
13. Kumaran, S., Sasikumar, T., Arockiakumar, R. and Srinivasa Rao, T., "Nanostructured titanium aluminides prepared by mechanical alloying and subsequent thermal treatment", Powder Technology, Vol. 185, pp. 124-130, (2008).
14. Erschbaumer, H., Podloucky, R., Rogl, P. and Temnitschka, G., "Atomic modelling of Nb, V, Cr, and Mn substitutions in γ-TiAl. I: c/aratio and site preference", Intermetallics, Vol. 1, pp. 99-106, (1993).
15. جرمن، ر.م، "متالورژی پودر"، ترجمه ناصریان ریابی، م. و حائریان اردکانی ع.، دانشگاه فردوسی مشهد، صفحات25-400، (1385).
16. Wang, Y.H., Lin, J.P., He, Y.H., Lu, X., Wang, Y.L. and Chen, G.L., "Microstructure and mechanical properties of high Nb containing TiAl alloys by reactive hot pressing", Journal of Alloys and Compounds, Vol. 461, pp. 367-372, (2008).
17. Appel, F., Paul, J.D.H.and Oehring, M., "Gamma titanium aluminide alloys, science and technology", Wiley-VCH Verlag and Co. KGaA, Boschstr, Weinheim, Germany, Vol. 12, pp. 40-77, (2011).
18. Reddy, R.G., Wen, X., and Divakar, M., "Isothermal Oxidation of TiAl Alloy", Metallurgical and Materials Transactions A, Vol. 32A, pp. 2357-2362, (2000).
19. Locci, I.E., Brady, M.P., MacKay, R.A. and Smith, J.W., "Very long term oxidation of Ti-48Al-2Cr-2Nb at 704 ◦C in air", Scripta Materialia, Vol. 37, pp. 761-766, (1997).
20. Schutze, M. and Hald, M., "Improvement of the oxidation resistance of TiAl alloys by using the chlorine effect", Materials Science and Engineering A, Vol. 239, pp. 847-858, (1997).