Abstract
High temperature wear and corrosion of engineering components is a major challenge in terms of surface degradation. A potential solution has been the use of thermal spray coating particularly nickel superalloy-based and ceramic-based in order to alter the surface properties and increase the life of such parts. The present paper entails the creation of Inconel 625 + 30% Al2 O3 composite coating on the substrates of SS-304 steel using the high-velocity oxy-fuel (HVOF) thermal spray technique. The as-sprayed coating was post-processed using microwaves in order to improve microstructural and mechanical properties. The characterization of the coatings was done using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD), and also using microhardness testing. The sliding wear behavior of the as-sprayed coating, the post-processed coating and the uncoated substrate of the substrate was analyzed using a pin-on-disc tribometer. The results indicated that an adherent and dense microstructure of low porosity of the as-sprayed coating existed. By joining hard Al2 O3 particles with the Inconel 625 matrix, the microhardness and wear resistance increased significantly as compared to the Inconel 625 substrate. Additional coating was furthered through the use of post-processing using microwaves to reduce defects and improve bonding between splats. The post-processed coating was the one that demonstrated the highest microhardness and least rate of wear, as per the samples under test. SEM analysis of the worn surfaces showed that the uncoated substrate and the as-sprayed coating exhibited the most predominant abrasive and oxidative wear mechanisms, besides, the post-processed coating had the most dependable and protective tribolayer. The findings indicate that microwave-processed Inconel 625 + Al2 O3 composite surface coating has the potential to enhance the surface properties of as well as tribological performance of SS-304 steel components that are exposed to harsh environmental conditions.