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


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.


aircraft overhaul high-temperature brazing aluminizing hybrid technology protective coatings 



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.


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Copyright information

© ASM International 2017

Authors and Affiliations

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

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