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Microstructure evolution of eutectic Nb–24Ti–15Si–4Cr–2Al–2Hf alloy processed by directional solidification

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Abstract

In this work, the near-eutectic Nb–24Ti–15Si–4Cr–2Al–2Hf (at%) alloy was directionally solidified at 1900 °C with withdrawal rates of 6, 18, 36, 50 mm·min−1 and then heat-treated at 1450 °C for 12 h. The microstructure evolution was investigated. The results show that the microstructure of the directionally solidified (DS) alloy is composed of Nbss + Nb5Si3 eutectics within the whole withdrawal rate range, while the variation of rates makes a great difference on the solidification routes, the morphology and size of Nbss + Nb5Si3 eutectic cells. With the increase in withdrawal rates, the petaloid Nbss + Nb5Si3 eutectic cells transform into granular morphology. After the heat treatment, a mesh structure Nbss is formed gradually which isolates the Nb5Si3, and the phase boundaries become smoother in order to reduce the interfacial energy. Moreover, two kinds of Nb5Si3 exist in the heat-treated (HT) samples identified by crystal form and element composition, which are supposed as α-Nb5Si3 and γ-Nb5Si3, respectively. This study exhibits significant merits in guiding the optimization of Nb–Si-based alloys’ mechanical properties.

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References

  1. Bewlay BP, Jackson MR, Lipsitt HA. The balance of mechanical and environmental properties of a multielement niobium–niobium silicide-based in situ composite. Metall Mater Trans A. 1996;27(12):3801.

    Article  Google Scholar 

  2. Bewlay BP, Lipsitt HA, Jackson MR, Reeder WJ, Sutliff JA. Solidification processing of high temperature intermetallic eutectic-based alloys. Mater Sci Eng A. 1995;192(2):534.

    Article  Google Scholar 

  3. Bewlay BP, Jackson MR, Zhao JC. Ultrahigh-temperature Nb-silicide-based composites. MRS Bull. 2003;28(9):646.

    Article  Google Scholar 

  4. Jackson MR, Bewlay BP, Rowe RG. High-temperature refractory metal-intermetallic composites. JOM. 1996;48(1):39.

    Article  Google Scholar 

  5. Bewlay BP, Lewandowksi JJ, Jackson MR. Refractory metal-intermetallic in situ composites for aircraft engines. JOM. 1997;49(8):44.

    Article  Google Scholar 

  6. Bewlay BP, Jackson MR, Subramanian PR. A review of very-high-temperature Nb-silicide-based composites. Metall Mater Trans A. 2003;34(10):2043.

    Article  Google Scholar 

  7. Bao J, Huang Q, Tang L, Geng T, Zhao XQ, Ma CL. Liquid–solid phase equilibria of Nb–Si–Ti ternary alloys. Chin J Aeronaut. 2008;21(3):275.

    Article  Google Scholar 

  8. Yuan SN, Jia LN, Su LF, Ma LM, Zhang H. The microstructure optimizing of the Nb–14Si–22Ti–4Cr–2Al–2Hf alloy processed by directional solidification. Mater Lett. 2012;84(10):124.

    Article  Google Scholar 

  9. Yuan SN, Jia LN, Su LF, Ma LM, Zhang H. The microstructure evolution of directionally solidified Nb–22Ti–14Si–4Cr–2Al–2Hf alloy during heat treatment. Intermetallics. 2013;38(14):102.

    Google Scholar 

  10. Kim WY, Tanaka H, Hanada S. Microstructure and high temperature strength at 1773 K of Nbss/Nb5Si3 composites alloyed with molybdenum. Intermetallics. 2002;10(6):625.

    Article  Google Scholar 

  11. Wang LG, Weng JF, Guan K, Su LF, Jia LN, Zhang H. Microstructure and mechanical properties of directionally solidified and heat treated Nb–14Si–24Ti–2Cr alloy. Mater Res Innov. 2012;16(4):276.

    Article  Google Scholar 

  12. Ma CL, Kasama A, Tan Y, Tanaka H, Tanaka R, Mishima Y, Hanada S. Synthesis of Nbss/Nb5Si3 in situ composites by mechanical milling and reactive spark plasma sintering. Mater Trans JIM. 2000;41(6):719.

    Article  Google Scholar 

  13. Kimura Y, Mishima Y, Yamaoka H, Sekido N. Processing, microstructure, and mechanical properties of (Nb)/Nb5Si3 two-phase alloys. Metall Mater Trans A. 2005;36(3):483.

    Article  Google Scholar 

  14. Kashyap S, Tiwary CS, Chattopadhyay K. Microstructure and mechanical properties of oxidation resistant suction cast Nb–Si–Al alloy. Mater Sci Eng A. 2013;559(1):74.

    Article  Google Scholar 

  15. Guo XP, Guan P, Ding X, Zhang J, Kusabiraki K, Fu HZ. Unidirectional solidification of a Nbss/Nb5Si3 in situ composite. Mater Sci Forum. 2005;475(5):745.

    Article  Google Scholar 

  16. Li XJ, Chen HF, Sha JB, Zhang H. The effects of melting technologies on the microstructures and properties of Nb–16Si–22Ti–2Al–2Hf–17Cr alloy. Mater Sci Eng A. 2010;527(23):6140.

    Article  Google Scholar 

  17. Ding F, Jia L, Yuan S, Su LF, Weng JF, Zhang H. Microstructure evolution of a hypereutectic Nb–Ti–Si–Cr–Al–Hf alloy processed by directional solidification. Chin J Aeronaut. 2014;27(2):438.

    Article  Google Scholar 

  18. Guo H, Guo X. Research progress in the directionally solidified microstructure and the eutectic solidification theory of niobium-based ultrahigh-temperature alloy. Mater Rev. 2007;21(4):56.

    Google Scholar 

  19. Wang L, Jia L, Cui R, Zheng LJ, Zhang H. Microstructure, mechanical properties and oxidation resistance of Nb–22Ti–14Si–2Hf–2Al–xCr alloys. Chin J Aeronaut. 2012;25(2):292.

    Article  Google Scholar 

  20. Jia LN, Ge JR, Zheng LJ, Sha JB, Zhang H. Microstructure and mechanical properties of the heat treated Nb–16Si–22Ti–2Hf–2Cr–2Al alloy prepared by vacuum induction melting. Acta Mater Compos Sin. 2011;28(5):22.

    Google Scholar 

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Acknowledgments

This study was financially supported by the National Natural Science Foundation of China (No. 51101005).

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Authors and Affiliations

  1. School of Materials Science and Engineering, Beihang Universtity, Beijing, 100191, China

    Zhen Li, Sai-Nan Yuan, Li-Na Jia, Bin Kong, Zhen Hong & Hu Zhang

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  1. Zhen Li
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  2. Sai-Nan Yuan
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  3. Li-Na Jia
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  4. Bin Kong
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  6. Hu Zhang
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Correspondence to Li-Na Jia.

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Li, Z., Yuan, SN., Jia, LN. et al. Microstructure evolution of eutectic Nb–24Ti–15Si–4Cr–2Al–2Hf alloy processed by directional solidification. Rare Met. 36, 472–477 (2017). https://doi.org/10.1007/s12598-015-0649-4

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  • DOI: https://doi.org/10.1007/s12598-015-0649-4

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