Inspection of ceramic materials

Ceramic materials represent a special challenge for nondestructive component testing. They differ significantly in composition, material properties, defect types, defect sizes, the manufacturing process, as well as in geometric properties from metals, which are more often tested with nondestructive methods. Some methods of nondestructive testing have been established for ceramic components for many years. These include visual inspection and dye penetrant testing, but also acoustic resonance testing, X-ray testing, and in some special cases ultrasonic testing. In addition, a number of new methods are currently being developed which can partially eliminate the disadvantages of existing technologies. These new methods include special acoustic methods, infrared transmission, optical coherence tomography, high-frequency eddy current technique, active thermography, microwave technique, and laser speckle photometry. All the methods mentioned above are examined and discussed in detail.