Effect of cobalt variation on microstructural and erosion performance of HVOF-sprayed WC–Co-Cr-Ni hard-faced coatings

Abstract

The research targets effects of microstructure and erosion behavior of the prepared WC–Co-Cr-Ni coatings deposited on Inconel 718 substrate by using HVOF equipment JDH2600 liquid fuel gun. The coatings were synthesized from different cobalt concentrations of 14%, 16%, and 18% respectively while maintaining chromium and nickel at a concentration of 2% each. This approach is to determine the various factors of cobalt concentration affecting microstructure and erosion resistance of the coatings. Microstructural depiction was performed using scanned electron microscope (SEM) and energy-dispersive x-ray spectroscopy (EDS) to study the distribution of WC particle and bonding between WC particles and the metal matrix. The work proves that increasing in the cobalt concentration provided the material with a more compact structure, which increases the mechanical characteristics of the coating and decreased porosity. Further on, durability tests in the form of erosion tests were carried out for 45°, 60°, and 90°. The WC-18Co-2Cr-2Ni spraying coating exhibits improved erosion resistance due to its enhanced toughness and bonding properties in an erosive environment. These results are significant in understanding how to maximize the performance of WC-based coatings for advanced applications.