Effect of electron beam remelting to microstructure and phase modification of HVOF and CGDS CoNiCrAlY coatings

conference paper

English

This paper deals and compare the mictrostructure of CoNiCrAlY coatings manufactured by the high-velocity oxygen-fuel (HVOF) and cold gas dynamic spraying (CGDS) deposition technique after electron beam (EB) remelting. HVOF and CGDS spraying method was used in order to obtain very dense and good adhesive CoNiCrAlY-coatings deposited onto nickel-based alloy. The electron beam remelting process is one of the most convenient processes to reduce the disadvantages of thermal spray coatings. The effect of high-energy electron beam irradiation on surface remelting and microstructural modification in CoNiCrAlY bond coats are investigated in this study. A subsequent remelting of the both HVOF and CGDS – coatings by electron beam irradiation has proven to minimize the porosity modifications in the morphology and the phase composition of the CoNiCrAlY bond coats. The surface was remelted up to a depth of approximately 100 . Scanning Electron Microscopy, light microscopy and X-ray Diffraction were performed to characterize the phase modification and morphology before and after treatment. The results obtained in this study show following: There are advantages at using the pulsed electron beam surface modification technique. EB-treatment provides a smooth surface with low porosity level. The as-sprayed CGDS and HVOF coatings exhibit similar microstructures. From these results, it appears that potential improvements of deposition the bond coat can be also achieved using low-temperature processing method such as CGDS.

Bond coat, cold spray, HVOF spraying, EB remelting, CoNiCrAlY coating

GAVENDOVÁ, P.; DLOUHÝ, I.; ČÍŽEK, J.; ČUPERA, J.; HANUSOVÁ, P.

2015

25. 5. 2015

Associazione Italia di Metallurgia

Italy

978-88-98990-03-0

Heat Treatment and Surface Engineering from tradition to innovation

NEUVEDENO

152

159

7