Advances in materials Research

  • 제7권1호
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  • Pages.17-28
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  • 2018
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  • 2234-0912(pISSN)
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  • 2234-179X(eISSN)
테크노프레스 (Techno-Press)
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Microstructures and hardness of model niobium-based chromium-rich cast alloys

  • 투고 : 2018.02.10
  • 심사 : 2018.07.06
  • 발행 : 2018.03.25
⟨ 이전 논문 다음 논문 ⟩

초록

Niobium is a candidate base for new alloys devoted to applications at especially elevated temperatures. Elaborating and shaping niobium-based alloys by conventional foundry may lead to mechanically interesting microstructures. In this work a series of charges constituted of pure elements were subjected to high frequency induction melting in cold crucible to try obtaining cast highly refractory Nb-xCr and Nb-xCr-0.4 wt.%Calloys(x=27, 34 and 37 wt.%). Melting and solidification were successfully achieved. The as-cast microstructures of the obtained alloys were characterized by electron microscopy and X-ray diffraction and their hardness were specified by Vickers macro-indentation. The obtained as-cast microstructures are composed of a body centered cubic (bcc) niobium dendritic matrix and of an interdendritic eutectic compound involving the bcc Nb phase and a $NbCr_2$ Laves phase. The obtained alloys are hard to cut and particularly brittle at room temperature. Hardness is of a high level (higher than 600Hv) and is directly driven by the chromium content or the amount of {bcc Nb - $NbCr_2$} eutectic compound. Adding 0.4 wt.% of carbon did not lead to carbides but tends to increase hardness.

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참고문헌

  1. Berthod, P. (2009), "High temperature properties of several chromium-containing Co-based alloys reinforced by different types of MC carbides (M=Ta, Nb, Hf and/or Zr)", J. Alloys Compd., 481(1-2), 746-754. https://doi.org/10.1016/j.jallcom.2009.03.091
  2. Bradley, E. (1988), Superalloys: A technical guide, ASM International, OH, U.S.A.
  3. Conrath, E. and Berthod, P. (2016), "Microstructures of binary Cr-xNi alloys ($0{\leq}Ni{\leq}50$ wt.%) in their ascast state and after high temperature exposure", Mater. High Temp., 33(2), 189-197. https://doi.org/10.1080/09603409.2016.1144317
  4. Cui, C., Ping, D., Gu, Y. and Harada, H. (2006), "A new Co-base superalloy strengthened by ${\gamma}^{\prime}$ phase", Mater. Trans., 47(8), 2099-2102. https://doi.org/10.2320/matertrans.47.2099
  5. Ding, R. and Jones I.P. (2008), "Mechanical properties and deformation behaviour of a niobium alloy with different carbon contents", Mater. Sci. Eng. A Struct. Mater. Prop., Microstruct. Process. A, 497(1-2), 301-308. https://doi.org/10.1016/j.msea.2008.07.038
  6. Donachie, M.J. and Donachie, S.J. (2002), Superalloys: A technical guide, 2nd Ed., ASM International, OH, U.S.A.
  7. Gebhardt, E., Fromm, E. and Benesovsky, F. (1972), "Refractory metals and alloys", Zeitschrift fur Werkstofftechnik, 3(4), 197-203. https://doi.org/10.1002/mawe.19720030407
  8. Gorr, B., Azim, M., Christ, H.J., Chen, H., Szabo, D.V., Kauffmann, A., & Heilmaier, M. (2016), "Microstructure evolution in a new refractory high entropy alloy W-Mo-Cr-Ti-Al", Metallurgical Mater. Trans. A Phys. Metallurgy Mater. Sci., 47(2), 961-970. https://doi.org/10.1007/s11661-015-3246-0
  9. Gorr, B., Burk, S., Depha, T., Somsen, C., Abu-Samra, H., Christ, H.J. and Eggeler, G. (2012), "Effect of Si addition on the oxidation resistance of Co-Re-Cr-alloys: Recent attainments in the development of novel alloys", J. Mater. Res., 103(1), 24-30.
  10. Guan, P., Guo, X. P., Ding, X., Zhang, J., Gao, L.M. and Kusabiraki, K. (2004), "Directionally solidified microstructure of an ultra-high temperature Nb-Si-Ti-Hf-Cr-Al alloy", Acta Metallurgica Sinica, 17(4), 450-454.
  11. Klauke, M., Mukherji, D., Gorr, B., da Trindade Filho, V.B., Rosler, J. and Christ, H.J. (2009), "Oxidation behaviour of experimental Co-Re-base alloys in laboratory air at $1000^{\circ}C$", J. Mater. Res., 100(1), 104-111.
  12. Kofstad, P. (1988), High Temperature Corrosion, Elsevier Applied Science, London, United Kingdom.
  13. Mishra, B., Ionescu, M. and Chandra, T. (2013), "Feasability of cast and wrought Co-Al-W-X gamma prime superalloys", Mater. Sci. Forum, 783-786, 1159-1164.
  14. Nembach, E. and Neite, G. (1985), "Precipitation hardening of superalloys by ordered ${\gamma}^{\prime}$- particles", Prog. Mater. Sci., 29(3), 177-319. https://doi.org/10.1016/0079-6425(85)90001-5
  15. Perepezko, J.H. (2009), "Alloys based on molybdenum or niobium may allow the high-temperature components of jet engines to run hotter and more efficiently at ${\leq}1300^{\circ}C$", Science, 326(5956), 1068-1069. https://doi.org/10.1126/science.1179327
  16. Sha, J., Hirai, H., Tabaru, T., Kitahara, A., Ueno, H. and Hanada, S. (2004), "High-temperature strength and room-temperature toughness of Nb-W-Si-B alloys prepared by arc-melting", Mater. Sci. Eng., A Struct. Mater. Prop., Microstruct. Process. A, 364(1-2), 151-158. https://doi.org/10.1016/j.msea.2003.08.014
  17. Shaffer, P.T.B. (1964), High-temperature Materials: Materials Index, Plenum Press Handbook, New York, U.S.A.
  18. Sims, C. and Hagel, W. (1972), The Superalloys, John Wiley and Sons, New York, U.S.A.
  19. Thoma, D.J., Chu, F., Peralta, P., Kotula, P.G., Chen, K.C. and Mitchell, T.E. (1997), "Elastic and mechanical properties of $Nb(Cr,V)_2$ C15 Laves phases", Mater. Sci. Eng., A Struct. Mater. Prop., Microstruct. Process. A, 239-240, 251-259. https://doi.org/10.1016/S0921-5093(97)00589-3
  20. Wojcik, C.C. (1998), "High-temperature niobium alloys", Adv. Mater. Process., 154(6), 27-30.
  21. Young, D. (2008), High Temperature Oxidation and Corrosion of Metals, Elsevier, Amsterdam, Netherlands.