This book deals with the investigation of plasma sprayed Yttria partially stabilized zirconia (Y-PSZ) as thermal barrier coating (TBC). The thermal barrier coating, as the name suggests, is a coating of material of low thermal conductivity value, low enough to make it capable to reduce heat from the hot working fluid to penetrate into the substrate in high temperature applications like diesel engines, gas turbines etc. The investigation has been made in terms of thermal behaviour and thermo-physical behaviour of plasma sprayed Y-PSZ coating over aluminium (12 % by wt. Si) substrate using intermediate bond coat of Al2O3. An attempt has been made to determine the thermal effectiveness of coating for different thicknesses of Y-PSZ layer using Finite Element Methodology (FEM) based ANSYS simulation. An experimental work has also been conducted to investigate the thermal behaviour of coating and the coated specimen as compared to uncoated one, through oxy-acetylene flame testing. Same flame heating test has been performed to subject the coated surface to cyclic thermal loading conditions and flame punching experiment and the thermo-physical behaviour of the coating has been examined.