**Abstract**

An upsurge in the demand of higher power generation has been observed in the last few decades. Consequently, the mechanical components of power generation are forced to operate in the extreme working conditions for longer duration, which results in the accelerated wear and corrosion of the material. Conventional material such as grey cast iron (GCI) is a preferred material of components used for power generation at high temperature. Grey cast iron exhibits poor wear and corrosion resistance at high temperature. On the other hand, an advanced material such as Alloy-718 is capable to withstand the high-temperature wear and oxidation for prolonged duration of time. In the current research, high temperature corrosion and erosive wear performance of grey cast iron (GCI) components has been enhanced by depositing a bi-layerAlloy-718/NiCrAlY coating by using high velocity oxy-fuel (HVOF) thermal spray process. Furthermore, the high temperature corrosion and erosion behaviour of GCI substrate and the deposited coating has been discussed. The various characterization techniques such as scanning electron microscopy (SEM) X-ray diffraction, and Vickers micro-hardness testing were conducted for the GCI substrate and Alloy-718 coating, respectively. The Alloy-718 coting showed the increased resistance against high-temperature erosion and oxidation, which can be attributed to its good bonding with the substrate, high hardness and formation of protective phases at high-temperature.

**Keywords:** high-temperature, turbocharger, Alloy-718/NiCrAlY, HVOF, grey cast iron
