Investigating methods of thermal barrier coating evaluation using non-destructive methods

The main focus of this review article is related to non-destructive testing methods used to evaluate thermal spray nanocoatings. These techniques include eddy currents, infrared imaging, phase thermal emission spectroscopy, acoustic, photoacoustic, mid-infrared reflection, electrochemical impedance spectroscopy, photoluminescence piezospectroscopy, and interferometry techniques. These techniques have been used to identify surface defects and interface between ceramic layers and metal interface, its shape, size and location and to measure porosity and thickness.