COMPARISON OF CoNiCrAlY COATINGS PRODUCED BY HVOF AND CGDS-SPRAYING TECHNIQUE

conference paper

English

CoNiCrAlY bond coats manufactured by the high-velocity oxygen-fuel spraying (HVOF) and cold gas dynamic spraying (CGDS) deposition technique have been investigated and comparison of phase modification is presented in the paper. Even though both techniques accelerate powder particles with high kinetic energy, the resulting coatings differ considerably in their microstructures. In the former, high pressure is created by burning gases such as acetylene, propane or kerosene at high pressure and generating high temperature (3500 to 4500 C) in the gun. This gives high acceleration to powder particles which melt and deposit on substrate layer by layer with splat cool mechanism. On the other hand, large kinetic energy is generated in cold spray by passing carrier gases such as He or N2 through converging-diverging nozzle, with lower gun temperature of around 600 C. Here the particles are not liquid droplets because of lower temperature and the deposition mechanism is not a splat cooling, but a high impact of solid particles, which results in plastic deformation, making very adherent coating. In this work, CoNiCrAlY powder was deposited on Inconel 718 substrate using HVOF and CGDS deposition process. The bond coats microstructural features were characterized by means of SEM and XRD analyses. The experimental results demonstrated that the CoNiCrAlY bond coats prepared by both HVOF and CGDS technique displayed the lower porosity for CGDS microstructure, and therefore CGDS represents an interesting and promising alternative for their manufacturing.

TBC, Bond coat, CoNiCrAlY coatings, cold spray, HVOF spraying

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

2015

3. 6. 2015

Tanger Ltd.

Brno

978-80-87294-62-8

METAL 2015

NEUVEDENO

152

158

6