Thermal sprayed coatings for hot corrosion protection of exhaust valves in naval diesel engines

Microstructural characteristics of each coating in the as-sprayed conditions were evaluated by measuring porosity and microhardness. Hot corrosion tests were performed on samples covered with a mixture of Na2SO4 and V2O5 and placed in a furnace at 700 °C in air for different times (5, 25, 50, 75 and 100 h). Finally, EDS and XRD analyses were carried out on the corroded samples.