Assessment of Wear-Resistance in Hydro Turbine Steel: The Impact of Sediment Erosion on a Metal-Ceramic Coating

Abstract Wear of the components of the hydropower plant is mainly because of the striking of rigid silt particles which is carried out with the water. The present study focuses on the development of a ceramic and metal-ceramic protective coating using flame spray and high-velocity oxy-fuel (HVOF) coating technique. A slurry erosion testing equipment has been utilized to examine the wear behavior of specimens with and without coating. Experiments are performed on the coating compositions developed by varying the weight percentage of Co-NiCrAlY (metal) and Al 2 O 3 (ceramic). The erosive behavior of all the specimens has been investigated at impact angles 30°, 45°, 60°, and 90°, impact velocities varying between 6 to 12 m/s. The metallurgical characterization of the developed coatings has been performed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) analysis. Vickers hardness measurement and surface wettability analysis have been conducted for the mechanical characterization of the coatings. The metal-ceramic coating shows overall better erosion-resistive behavior due to the combined shielding effect and reduction in impact energy of the ceramic and metal respectively. The acquired findings pertain to the refinement of metallurgical, microstructural, and mechanical attributes of the investigated specimen.