Abstract
In situ observation of the mechanical failure behavior was conducted for different kinds of the plasma sprayed thermal barrier coating (TBC) systems by means of an optical microscopy under the static loadings at ambient temperature and 900℃; as the most fundamental aspect, in order to clarify the failure mechanism of TBCs. Several kinds of TBC systems were prepared by using different coating parameters such as the sorts of top-coat powder, heat-treatment condition and so forth. Mechanical tensile or compressive loading was applied progressively to the TBC specimen in the axial loading test. The influence of TBC microstructure and testing temperature on the crack initiation and propagation behavior was investigated in detail. Furthermore, the TBC failure was quantitatively evaluated in relation with the mechanical strain applied on TBC systems.
