Matrix Transformation in Boron Containing High-Temperature Co–Re–Cr Alloys

  • Pavel Strunz
  • Debashis Mukherji
  • Přemysl Beran
  • Ralph Gilles
  • Lukas Karge
  • Michael Hofmann
  • Markus Hoelzel
  • Joachim Rösler
  • Gergely Farkas
Article
  • 39 Downloads

Abstract

An addition of boron largely increases the ductility in polycrystalline high-temperature Co–Re alloys. Therefore, the effect of boron on the alloy structural characteristics is of high importance for the stability of the matrix at operational temperatures. Volume fractions of ε (hexagonal close-packed—hcp), γ (face-centered cubic—fcc) and σ (Cr2Re3 type) phases were measured at ambient and high temperatures (up to 1500 °C) for a boron-containing Co–17Re–23Cr alloy using neutron diffraction. The matrix phase undergoes an allotropic transformation from ε to γ structure at high temperatures, similar to pure cobalt and to the previously investigated, more complex Co–17Re–23Cr–1.2Ta–2.6C alloy. It was determined in this study that the transformation temperature depends on the boron content (0–1000 wt. ppm). Nevertheless, the transformation temperature did not change monotonically with the increase in the boron content but reached a minimum at approximately 200 ppm of boron. A probable reason is the interplay between the amount of boron in the matrix and the amount of σ phase, which binds hcp-stabilizing elements (Cr and Re). Moreover, borides were identified in alloys with high boron content.

Keywords

High-temperature alloys Phase transformation Neutron diffraction In situ studies Scanning electron microscopy (SEM) 

Notes

Acknowledgements

The authors thank MLZ Garching, Germany, and CANAM (NPI Řež, CZ MSMT infrastructural project No. LM2015056), Czech Republic, for providing the beamtime for neutron scattering measurements and tests. P. Strunz, P. Beran and G. Farkas acknowledge support by the GACR project no. 14-36566G. The authors would like to thank the German Research Foundation (DFG) for providing the financial support for the joint Co–Re alloy development project at TU Braunschweig and TU München (RO 2045/31-1 and GI 242/4-1, respectively).

References

  1. 1.
    J. Rösler, D. Mukherji, T. Baranski, Adv. Eng. Mater. 9, 876 (2007)CrossRefGoogle Scholar
  2. 2.
    D. Mukherji, P. Strunz, R. Gilles, M. Hofmann, F. Schmitz, J. Rösler, J. Mater. Lett. 64, 2608–2611 (2010)CrossRefGoogle Scholar
  3. 3.
    D. Mukherji, P. Strunz, S. Piegert, R. Gilles, M. Hofmann, M. Hoelzel, J. Rösler, Metall. Mater. Trans. 43A, 1834–1844 (2012)CrossRefGoogle Scholar
  4. 4.
    D. Mukherji, J. Rösler, J. Wehrs, P. Strunz, P. Beran, R. Gilles, M. Hofmann, M. Hoelzel, H. Eckerlebe, L. Szentmiklósi, Z. Mácsik, Metall. Mater. Trans. 44A, 22–30 (2013).  https://doi.org/10.1007/s11661-012-1363-6 CrossRefGoogle Scholar
  5. 5.
    R. Gilles, D. Mukherji, L. Karge, P. Strunz, P. Beran, B. Barbier, A. Kriele, M. Hofmann, H. Eckerlebe, J. Roesler, J. Appl. Cryst. 49, 1253–1265 (2016).  https://doi.org/10.1107/S1600576716009006 CrossRefGoogle Scholar
  6. 6.
    R. Gilles, P. Strunz, D. Mukherji, M. Hofmann, M. Hoelzel, J. Roesler, J. Phys. Conf. Ser. 340, 012052 (2012).  https://doi.org/10.1088/1742-6596/340/1/012052 CrossRefGoogle Scholar
  7. 7.
    D. Mukherji, J. Roesler, M. Kruger, M. Heilmaier, M.-C. Bolitz, R. Volkl, U. Glatzel, L. Szentmiklosi, Scr. Mater. 66, 60–63 (2012)CrossRefGoogle Scholar
  8. 8.
    M.C. Boelitz, M. Brunner, R. Voelkl, D. Mukherji, J. Roesler, U. Glatzel, Int. J. Mat. Res. 103, 554–558 (2012)CrossRefGoogle Scholar
  9. 9.
    D. Mukherji, R. Gilles, L. Karge, P. Strunz, P. Beran, H. Eckerlebe, A. Stark, L. Szentmiklosi, Z. Macsik, G. Schumacher, I. Zizak, M. Hofmann, M. Hoelzel, J. Roesler, J. Appl. Cryst. 47, 1417–1430 (2014)CrossRefGoogle Scholar
  10. 10.
    D. Mukherji, P. Strunz, R. Gilles, L. Karge, J. Rosler, Kovove Mater. 53, 287–294 (2015).  https://doi.org/10.4149/km20154287 Google Scholar
  11. 11.
    M. Hofmann, R. Schneider, G.A. Seidl, J. Kornmeier, R. Wimpory, U. Garbe, H.G. Brokmeier, Phys. B 385–368, 1035 (2006)CrossRefGoogle Scholar
  12. 12.
    R. Gilles, M. Hoelzel, M. Schlapp, F. Elf, B. Krimmer, H. Boysen, H. Fuess, Z. Kristallogr. Suppl. 23, 183 (2006)CrossRefGoogle Scholar
  13. 13.
    M. Hoelzel, A. Senyshyn, N. Juenke, H. Boysen, W. Schmahl, H. Fuess, Nucl. Instrum. Methods Phys. Res. A 667, 32–37 (2012).  https://doi.org/10.1016/j.nima.2011.11.070 CrossRefGoogle Scholar
  14. 14.
    M.C. Paulisch, N. Wanderka, G. Miehe, D. Mukherji, J. Rösler, J. Banhart, Characterization of borides in Co–Re–Cr-based high-temperature alloys. J. Alloy. Compd. 569, 82–87 (2013)CrossRefGoogle Scholar
  15. 15.
    J. Rodríguez-Carvajal, Phys. B Condens. Matter. 192, 55 (1993)CrossRefGoogle Scholar
  16. 16.
    P. Beran, D. Mukherji, P. Strunz, R. Gilles, M. Hofmann, L. Karge, O. Dolotko, J. Rösler, Met. Mater. Int. 22, 562–571 (2016).  https://doi.org/10.1007/s12540-016-5697-2 CrossRefGoogle Scholar
  17. 17.
    A.M. Beltran, Cobalt-Base Alloys, in Superalloys II, ed. by C.T. Sims, N.S. Stoloff, W.C. Hagel (Wiley, New York, 1987), p. 141Google Scholar

Copyright information

© The Korean Institute of Metals and Materials 2018

Authors and Affiliations

  1. 1.Nuclear Physics Institute of the CASŘežCzech Republic
  2. 2.Institut für WerkstoffeTechnische Universität BraunschweigBraunschweigGermany
  3. 3.Heinz Maier-Leibnitz Zentrum (MLZ)Technische Universität MünchenGarchingGermany
  4. 4.Department of Physics of Materials, Faculty of Mathematics and PhysicsCharles UniversityPragueCzech Republic

Personalised recommendations