On deposition of Waspaloy coatings by cold spray

Abstract

The deposition of pore free and highly adhered Ni and Co superalloy coatings is of great interest for engine design and gas turbine applications, both in case of maintenance repair and overhaul operations as well for mechanical and chemical protection purposes in aeronautics and energy applications. This study would like to give a wide overview about the capability of cold spray technology on this topic: two different commercially available deposition systems, Sulzer-CGT Kinetiks 4000 and Plasma Giken PCS-1000, were compared, and deposition processes with both nitrogen and helium as carrier gas have been explored. Microstructural investigation, microhardness and adhesion results are reported to depict a preliminary scenario of coating properties. Fully dense coatings with thickness >1 mm and adhesion >50 MPa are obtained using helium, while quite porous, 20 MPa adhered coatings are obtained using nitrogen. Finally, general considerations about the potential applicability of those coatings for repair purpose in aerospace applications are pointed out.

Keywords:

• Nickel alloys
• Waspaloy
• Coating microstructure
• MRO
• PCS-1000
• Kinetiks

Acknowledgements

This work has been carried out within the project LPT Waspaloy Casing Repair co-funded by the P.O. PUGLIA 2007-2013 CONTRATTI DI PROGRAMMA REGIONALI - FE6.102933. The authors would like to thank Alessandro Surpi for technical support and fruitful discussion about coating characterisation.