Abstract
Thermal Barrier Coatings (TBCs) is one of the surface modification techniques. Thermal barrier coat in triplex structures were deposited on hestalloy x, Inconel 617 and IN 738.(nickle base alloys). The ceramic coat was partially stabilized zircona (YSZ 7-8% Y2O3). and bond coat of nickel base alloy, namely NiCoCrAlY alloy. The triplex structure was designed to investigate the interdiffusion of elements through the bond coat alloy under and over the ceramic coat which is believed to be one of failure mechanisms of TBCs during cyclic oxidation. Optical microscopy, Scanning Electron Microscopy (SEM) and X-Ray Energy Dispersive analysis (EDX) were used in this investigation