Comparison of In-Flight Particle Characteristics and Coating Properties While Spraying NiCrBSi Powder with Different Spraying Processes

Abstract The aim of this study was to compare different processes for a spraying NiCrBSi powder in order to understand how the coating properties are influenced by the particle characteristics. For that, three processes were tested: atmospheric plasma, HVOF and flame spraying. The plasma torch was a classical F4 gun from Sulzer-Metco, the HVOF gun was the CDS system manufactured by Sulzer-Metco and the flame spray gun was a Castolyn 8000 system. For each spraying process, the particles were analyzed using the DPV 2000 (Technar Ltd) at the distance corresponding to the coating build up. Particles velocity and temperature data were then correlated to the coating quality. Results indicate that the choice of the spraying technique induces important modifications in the coating properties in terms of adherence, porosity level, hardness and Young modulus. Changes in particle velocity and temperature are the key parameters determining the coating properties.