Abstract <p>In the present study, a Co-based surfacing alloy (Co–Ni–Cr–W–C) was thermally deposited (HVOF) on Inconel-718 substrate. HVOF-sprayed coatings have inhomogeneity (porosity, unmelted particles) and are mechanically bonded to the substrate. Therefore, a novel susceptor assisted microwave-hybrid heating process was suggested through this investigation as an effective post-treatment technique to enhance the properties of thermally sprayed coatings in an energy efficient manner. The study highlights the importance of microwave post-treatment parameters, particularly temperature, in controlling coating properties such as morphology, porosity, carbide formation, microhardness, abrasive wear and corrosion behaviour for the first time. The coatings were subjected to microwave post-treatments at five different temperatures (500, 700, 900, 1100 and 1300&#xa0;°C). Microwave post-treatment at higher temperatures (1300&#xa0;°C) resulted in significant increase in the microhardness (by 66%), adhesion strength (85%), abrasion wear (by 49%) and corrosion resistance (by 62.5%) compared to HVOF coating. This improvement in properties can be attributed to the densification and formation of essential carbides (Cr₂₃C₆ and WC) after microwave post-treatment at higher temperatures (1300&#xa0;°C). The intrinsic mechanism of microwave post-treatment and its improved properties have been discussed. Overall, the study emphasizes the significance of microwave post-treatment in optimising the properties of Co-based HVOF coatings on Inconel-718, by presenting promising possibilities for its application in various fields.</p> Graphical Abstract <p></p>