Spallation of the plasma-sprayed thermal barrier coatings[PS-TBC] used in land-based gas turbine engines,although not detrimental to the components,is costly to the power generation industries.The spallation occurs during cooling from service temperatures as a result of the stress caused by thermal expansion mismatch between the supperalloy bondcoat and ceramic topcoat.This situation is made worse by the formation of the interfacial protective oxide scale and secondary oxide between the two coating. As the component is cooled, the thermal expansion mismatch causes tensile stress to develop across the ceramic topcoat and the oxide interface due to the undulation contour of the interface, which is a characteristic of the plasma-sprayed coation. The formation of the protective oxide scale is necessary in order to allow the TBC to function properly. Also, the dense, uniform, slow growing protective oxide is predictable and does not contribute greatly to the spallation of the TBC. The secondary oxides, however, are not a requirement for the TBC. These oxides are often porous, non-uniformed and grow at na unpredictable rate depending on the state of the bondcoat and the protective scale. The porous structure, depending on the shape and size of these defects, promotes crack initiation during cooling when the tensile stress is applied across the interface. The non-uniformed thickness of the secondary oxides and their fast growth cause variation in the stress along to oxide scale, making the coating spallation unpredictable. It is possible to reduce, or even, eliminate the formation of these unwanted secondary oxides by altering the bondcoat structure. This can be done by selecting suitable materials, fabrication processes and, possibly, heat treatment. The improved TBC system will prolong the life of the coatings and the turbine components. It will also reduce the damage of the components caused by downstream erosion of the spalled segments.