Solid Particle Erosion Behaviour of Plasma-Sprayed (WC–Co)/(Cr₃C₂–NiCr) Coatings

This study reports the high-temperature erosion behaviour of plasma-sprayed 35% (WC–Co)/65% (Cr₃C₂–NiCr) coating on MDN-420 alloy. Plasma spray coatings have always played a pivotal role in enabling industries to combat problems of premature degradation of components that operate in harsh environments. (WC–Co) + (Cr₃C₂–NiCr) coating is investigated for erosion under various laboratory-simulated conditions. Coating surface is characterized by using an optical microscope, scanning electron microscope (SEM), and X-ray diffraction (XRD). Porosity, microhardness, surface roughness, and adhesion strength of the coating are measured. The solid particle erosion test is conducted at the temperatures of 300 °C, 500 °C and 700 °C with the impact angles of 30° and 90° by using Al₂O₃ as an erodent in the hot air jet erosion testing machine. The optical profilometer is used to evaluate the erosion volume loss of the coated and uncoated samples. It is observed that erosion resistance of the substrate is found to be higher than the coating at the different test temperatures. As the temperature increases, the erosion resistance of the coating is also increased at all the temperatures for both impact angles of 30° and 90°.The eroded coating surface morphology reveals that the generalized behaviour of the coating is ductile in nature.