Studies on Plasma Sprayed Thermal Barrier Coating with Increase in Coating Thickness

In this study, the nature of performance test like a bond test, wear test and hot corrosion test and its effects on plasma sprayed Yttria-stabilized zirconia and Al2O3 composite (50:50 compositions) coating on Aluminium 6061 substrate are carried out. The three topcoat thicknesses of 100µm, 200µm, and 300µm are used for the studies. In case of hot corrosion test, the substrates were spread by molten salt (55wt.% V2O5+45wt.%Na2SO4) which is kept in the furnace at 350 °C for 40 hours. The properties changed for the different bond thickness where for 200 µm wear properties become optimal and 300 µm the corrosion test remains optimal. There is an improvement in the bond strength and its optimal value is obtained for 100 µm topcoat thickness. The physics behind all three experiments are explained in this paper.