Micro-cracks detection of aircraft

To detect the micro-cracks of aircraft parts in inspection is one of important uses of thermal neutron radiography. Technique of tagging process is a preferable method to detect micro-cracks (approximately less than 200μm) of aircraft parts. The Neutron Radiography Group of the Korea Atomic Energy Research Institute has developed the tagging process for detection of micro-cracks based from surface to internal. A solution of gadolinium nitrate dissolved in drill water was used in advantage of absorption cross section of gadolinium. The solution mixed the same amount of mass with a gadolinium nitrate hexahydrate to drill water visually makes a trace of micro-cracks