Influence of the atmospheric plasma spraying parameters on the coating structure and the deposition efficiency of silicon powder

Abstract Silicon coatings are usually produced by atmospheric plasma spraying (APS) and used as bond coats in environmental barrier coatings. The deposition efficiency (DE) of silicon powders is generally at a low level APS processes. reasons for the DE values have not been sufficiently investigated literature. aim this study was to investigate detail influence process parameters on coating structure powder processed with APS. A size distribution f = –53 + 15 µm sprayed using three-cathode generator produce such gas type, flow rate current intensity were varied widely. Accordingly, power increased from P 19.4 51.3 kW, which allowed different melting evaporation degrees powder. Particle velocities temperatures measured particle diagnostic method. terms their surfaces structures electron scanning microscopy (SEM). porosities an image analysis system. determined. results show that led high range about v p 270–360 m/s. High T 2,650–3,390 °C porosity Φ 2% 15%. value significantly lower than reported changed 1.5% 28%. 28% 40% higher strong grit-blasting effect main reason lowest 1.5%. second 11.1%. Numerous melted particles semi-melted splashed upon impact substrate, resulting melt loss. In addition, solid cores semi-molten could bounce off, also resulted Splashing bouncing factors affecting parameter sets ranging 18.7%