Evaluation of fracture behavior in a plasma-sprayed ceramics coating by acoustic emission using laser interferometer

The laser interferometer enables us to detect accurate, quantitative and noncontact measurement of local velocity. By using laser interferometer in the acoustic emission (AE) measurement, the limitations of conventional PZT transducer are expected to be overcome. The purpose of this work is to measure AE during the thermal cycle test by laser interferometer and to evaluate fracture behavior in plasma-sprayed ceramics coatings onto steel substrate. The results showed that it is possible to use laser facility as acoustic emission measurement method. Moreover, by analyzing detected waves due to the AE source analysis, the fracture behavior of coatings during thermal cycle tests was quantitatively evaluated.