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Journal of Thermal Spray Technology

, Volume 26, Issue 7, pp 1659–1668 | Cite as

A Combined Brazing and Aluminizing Process for Repairing Turbine Blades by Thermal Spraying Using the Coating System NiCrSi/NiCoCrAlY/Al

  • M. NicolausEmail author
  • K. Möhwald
  • H. J. Maier
Peer Reviewed

Abstract

The repair and maintenance of components in the aerospace industry play an increasingly important role due to rising manufacturing costs. Besides welding, vacuum brazing is a well-established repair process for turbine blades made of nickel-based alloys. After the coating of the worn turbine blade has been removed, the manual application of the nickel-based filler metal follows. Subsequently, the hot gas corrosion-protective coating is applied by thermal spraying. The brazed turbine blade is aluminized to increase the hot gas corrosion resistance. The thermal spray technology is used to develop a two-stage hybrid technology that allows shortening the process chain for repair brazing turbine blades and is described in the present paper. In the first step, the coating is applied on the base material. Specifically, the coating system employed here is a layer system consisting of nickel filler metal, NiCoCrAlY and aluminum. The second step represents the combination of brazing and aluminizing of the coating system which is subjected to a heat treatment. The microstructure, which results from the combined brazing and aluminizing process, is characterized and the relevant diffusion processes in the coating system are illustrated. The properties of the coating and the ramifications with respect to actual applications will be discussed.

Keywords

aircraft overhaul high-temperature brazing aluminizing hybrid technology protective coatings 

Notes

Acknowledgments

The work presented here was supported by the German Research Foundation (DFG) within the scope of the sub-project B1 “Near-net shape turbine blade repair using a joining and coating hybrid process” of the Collaborative Research Centre (SFB 871 “Product Regeneration”). Thanks go to the DFG for their support.

References

  1. 1.
    J. McGraw, R. Anton, G. Deventer, A. Burns, Advancements in Gas Turbine Vane Repair, Proc. of PWR 2006: ASME 2006 Power Conference, May 2–4, 2006 (Atlanta, Georgia), Power Division, 2006, p 385-389Google Scholar
  2. 2.
    X. Huang, W. Miglietti, Wide Gap Braze Repair of Gas Turbine Blades and Vanes - A Review, J. Eng. Gas Turbines Power, 2011, 134(1), p 010801-010801-17Google Scholar
  3. 3.
    W.A. Demo, S. Ferrigno, S. Budinger, E. Huron, Improving Repair Quality of Turbine Nozzles Using SA650 Braze Alloy, Superalloys 2000, T.M. Pollock, R.D. Kissinger, K. A. Bowman, M. McLean, S. Olson, J.J. Schirra, Ed., TMS (The Minerals, Metals & Materials Society), 2000, p 713-718Google Scholar
  4. 4.
    M.B. Henderson, D. Arrell, R. Larsson, M. Heobel, and G. Marchant, Nickel-Based Superalloy Welding Practices for Industrial Gas Turbine Applications, Sci. Technol. Weld. Join., 2004, 9(1), p 13-21CrossRefGoogle Scholar
  5. 5.
    R. Stolle, Conventional and Advanced Coatings for Turbine Airfoils, MTU Aero Engines Munich http://www.academia.edu/7789702/Conventional_and_advanced_coatings_for_turbine_airfoils, 2004, Accessed 14 December 2016
  6. 6.
    Y. Itoh, M. Saitoh, and Y. Ishiwata, Aluminizing Behaviours of Vacuum Plasma Sprayed MCrAlY Coatings, J. Eng. Gas Turbines Power, 2002, 124, p 270-275CrossRefGoogle Scholar
  7. 7.
    Y. Itoh and M. Saitoh, Mechanical Properties of Overaluminized MCrAlY Coatings at Room Temperature, J. Eng. Gas Turbines Power, 2005, 127, p 807-813CrossRefGoogle Scholar
  8. 8.
    D.B. Miracle, The Physical and Mechanical Properties of NiAl, Overview No. 104, Acta Metall. Mater., 1993, 41, p 649-684CrossRefGoogle Scholar
  9. 9.
    Z. Zhan, Y. He, L. Li, H. Liu, and Y. Dai, Low-Temperature Formation and Oxidation Resistance of Ultrafine Aluminide Coatings on Ni-Base Superalloy, Surf. Coat. Technol., 2009, 203, p 2337-2342CrossRefGoogle Scholar
  10. 10.
    M. Pytel, M. Góral, A. Nowotnik, J. Sieniawski, M. Drajewicz, and M. Ziaja, Heat Treatment and CVD Aluminizing of Ni-Base René 80 Superalloy, J. Achiev. Mater. Manuf. Eng., 2012, 51(1), p 30-38Google Scholar
  11. 11.
    J.R. Nicholls, N.J. Simms, W.Y. Chan, and H.E. Evans, Smart Overlay Coatings - Concept and Practice, Surf. Coat. Technol., 2002, 149, p 236-244CrossRefGoogle Scholar
  12. 12.
    Fr.-W. Bach, K. Möhwald, C. Bach, U. Holländer, Thermally Sprayed Filler Metal Coatings for High Temperature Brazing, Thermal Spray 2004: Advances in Technology and Application, on CD-Rom, ASM International, May 10–12, 2004 (Osaka, Japan), ASM International, 2004, p 1129Google Scholar
  13. 13.
    M. Nicolaus, K. Möhwald, Fr-W Bach, and H.J. Maier, Heat Treatment of Thermal Sprayed Ni-Base-Fillermetal/NiCrAlY-Coating Systems for Repairing Turbine Blades, Therm. Spray Bull., 2013, 6(2), p 119-123Google Scholar
  14. 14.
    M. Nicolaus, K. Möhwald, and H.J. Maier, Combined Brazing and Alitising Process for Thermally Sprayed Ni-Based Alloys for the Repair of Turbine Blades, Therm. Spray Bull., 2015, 8(1), p 56-61Google Scholar
  15. 15.
    G. Petzow, Metallographisches, Keramographisches, Plastographisches Ätzen, Materialkundlich-Technische Reihe (1), Gebrüder Bornträger Berlin, Stuttgart, 1994, p. 65 (in German)Google Scholar
  16. 16.
    I. Ansara, N. Dupin, H.L. Lukas, and B. Sundman, Thermodynamic Assessment of the Al-Ni System, J. Alloys Compd., 1997, 247, p 20-301CrossRefGoogle Scholar
  17. 17.
    A.J. McAlister, The Al-Co (Aluminium-Cobalt) System, J. Phase Equilib., 1989, 10(6), p 646-650Google Scholar
  18. 18.
    B. Grushko and B.Z. Weiss, Structure of Vacuum Brazed BNi-5 Joint of Inconel 718, Metall. Trans. A, 1984, 15A, p 609-620CrossRefGoogle Scholar
  19. 19.
    P. Groot and E. Franconi, Tensile Tests and Metallography of Brazed AISI, 3316L Specimens After Irradiation, J. Nucl. Mater., 1994, 211, p 149-155CrossRefGoogle Scholar
  20. 20.
    E. Lugscheider, V. Dietrich, and J. Mittendorf, Wide Joint Clearance Brazing with Nickel-Base Filler Metals, Weld. Res. Suppl., 1988, 2, p 47-5Google Scholar
  21. 21.
    E. Lugscheider and K.-D. Partz, High Temperature Brazing of Stainless Steel with Nickel-Base Filler Metals, Weld. Res. Suppl., 1983, 6, p 160-164Google Scholar
  22. 22.
    A. Khorram, O. Fakhraei, and M.J. Torkamany, Laser Brazing of Inconel 718 and Inconel 600 with BNi-2 Nickel-Based Filler Metal, Int. J. Adv. Manuf. Technol., 2017, 88, p 2075-2084CrossRefGoogle Scholar
  23. 23.
    J. Lopes do Nascimento, C. Barbosa, J. L. Fernandes, Effect of Different Heat Treatment Conditions on the Microstructure and Mechanical Properties of Inconel 718 Based Super Alloy Used in Petroleum Production, Praktische Metallographie, 2009, 46(12), p 640-656Google Scholar
  24. 24.
    B. Baufeld, Mechanical Properties of INCONEL 718 Parts Manufactured by Shaped Metal Deposition (SMD), J. Mater. Eng. Perform., 2012, 21(7), p 1416-1421CrossRefGoogle Scholar
  25. 25.
    L.C.M. Valle, L.S. Araújo, S.B. Gabriel, J. Dille, L.H.de Almeida, The Effect of δ Phase on the Mechanical Properties of an Inconel 718 Superalloy, J. Mater. Eng. Perform., 2013, 22(5), p 1512-1518Google Scholar
  26. 26.
    D. Česnik1, V. Bratuš, B. Kosec, J. Rozman, M. Bizjak, Heat treatment and fine-blankin Inconel 718, RMZMaterials and Geoenvironment, 2008, 55(2), p 163-172Google Scholar
  27. 27.
    G. Yang, Y. Xu, L. Jiang, and S. Liang, High Temperature Tensile Properties and Fracture Behaviour of Cast Nickel-Base K445 Superalloy, Prog. Nat. Sci.: Mater. Int., 2011, 21, p 418-425CrossRefGoogle Scholar
  28. 28.
    M. Nicolaus, B. Rottwinkel, K. Möhwald, C. Nölke, S. Kaierle, H. J. Maier, V. Wesling, Future Regeneration Processes for High Pressure Turbine Blades, Deutscher Luft- und Raumfahrtkongress, Sept 22–24, 2015 (Rostock, Germany), Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn, 2015, http://d-nb.info/1078170312
  29. 29.
    W. Lih, E. Chang, B.C. Wu, and C.H. Chao, The Effect of Pack-Aluminization on the Microstructure of MCrAlY and the Performance of Thermal Barrier Coatings, Surf. Coat. Technol., 1992, 50, p 277-288CrossRefGoogle Scholar
  30. 30.
    M. Harmelin, Al-O-Zr Ternary Phase Diagram Evaluation, in MSI Eureka, Effenberg, G. (Ed.), MSI, Materials Science International Services GmbH, Stuttgart, 1993Google Scholar
  31. 31.
    Y.T. Zhao and G.X. Sun, In Situ Synthesis of Novel Composites in the System Al-Zr-O, J. Mater. Sci. Lett., 2001, 20, p 1859-1861CrossRefGoogle Scholar
  32. 32.
    Fr.-W. Bach, K. Möhwald, U. Holländer, Physico-Chemical Aspects of Surface Activation During Fluxless Brazing in Shielding-Gas Furnaces, Key Eng. Mater., 2010, 438, p 73-80Google Scholar
  33. 33.
    Fr.-W. Bach, K. Möhwald, U. Holländer, J. Schaup, C. Roxlau, A. Langohr, Boron and Phosphorous Free Nickel Based Filler Metals for Brazing Stainless Steel in Shielding Gas Furnaces, Int. J. Mater. Res., 2011, 8, p 964-971Google Scholar

Copyright information

© ASM International 2017

Authors and Affiliations

  1. 1.Institut für Werkstoffkunde (Materials Science)Leibniz Universität HannoverGarbsenGermany

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