Effect of Double Electron Beam Remelting on Microstructure of HVOF and CGDS Bond Coat

Abstract

This work focuses to investigate the influence of the parameters used in electron beam (EB) remelting including the effect of double remelting of CoNiCrAlY coatings fabricated on Nickel based super alloy substrates by using the high velocity oxygen-fuel (HVOF) and cold gas dynamic spraying (CGDS) methods. The microstructures of as sprayed and remelted coatings were investigated by scanning electron microscopy and the phase analysis by X-ray diffraction (XRD). The results obtained show that there are advantages at using the pulsed EB surface modification technique. Double EB treatment provides a smooth surface and low porosity level and at last but not least this study demonstrate that low-temperature processing of CoNiCrAlY bond coat represents an interesting and promising alternative for their manufacturing.