The Influence of Spray Parameters on Ni20Cr Coating Properties Using On-line Optimization Process

Abstract

Abstract Thermal and kinetic history of particles inside the jet plume of atmospheric plasma spray (APS) provide the particles with a certain velocity and temperature prior to the impact onto the substrate. Adjusting these velocity and temperature allows to control final coating's properties. The properties of the obtained coatings mostly depend on particle's conditions prior to the impingement. A set of experiments were done in order to optimize an atmospheric plasma process by means of an online monitoring system. The study is done by changing some spraying parameters that certainly affect the velocity and the temperature of the in-flight particles. Plasma gas flow rates and spraying distance were the parameters changed in this work, whereas all the other spraying conditions were kept constant. On-line monitoring system Spray-Watch (Oseir Ltd.) was used to achieve the parameters optimization by the measurement of velocity, temperature and spatial distribution of the Ni20Cr inflight particles. The study of the coated samples includes microstructure characterization by means of Optical Microscopy (OM), Scanning Electron Microscopy (SEMEDS) and X-ray diffraction to study the effect of the spraying parameters in phase composition. Roughness measurements and mechanical properties are also included.