Detection of hidden defects by lateral thermal flows

In this work a new approach/method for detection of hidden defects by lateral thermal flows is proposed. The method is based on propagation of the thermal wave in a lateral direction in the sample volume and observation of the surface thermal distribution. This approach allows to reveal the hidden defects/cracks which are not detectable by conventional thermal inspection methods. The experimental investigations were conducted on steel samples with the defects which do not satisfy the detection criteria empirically established for thermal methods. The defects were successfully revealed. The proposed technique has a high sensitivity to hidden structures and can be applied in industrial inspection procedures.