Effect of Different Post Processing Techniques on Microstructure and Mechanical Properties of Atmospheric Plasma Sprayed WC-17Co Coatings

Atmospheric plasma sprayed coatings demonstrate high fracture toughness and microhardness properties. Thus, they are effective in minimizing erosion-induced damage in the machinery industry. In this study, WC-17Co coatings were deposited on SS-316L stainless steel substrate using the atmospheric plasma technique with a TriplexPro-210 gun. To enhance their microstructural and mechanical properties, several post-heat treatment operations were carried out using different types of thermal energy sources, such as laser, plasma, and inert atmosphere annealing. Microstructural and phase analysis of the coatings was performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS). Moreover, a thorough mechanical characterization was conducted to evaluate microhardness, contact elastic modulus, and fracture toughness. The study found that the post-heat processing operations improved the hardness and fracture toughness values of the coating layers compared to as-sprayed WC-17Co coating layers. The increase in mechanical properties is attributed to the reduction in microstructural defects. This research has significant implications in industries where coatings play vital roles in safeguarding and improving the performance of parts.