Microwave excitation for thermographic NDE: an experimental study and some theoretical evaluations

The theme of microwave heating for thermographic nondestructive evaluation has been addressed experimentally. Slabs and sandwiches, made of Kevlar or fiberglass, containing artificial defects were heated by means of cavity applicators fed by 2.45 GHz high microwave power (600-1,700 W). The results, compared with that obtained using X-ray, ultrasound, and infrared excited thermography, showed the effectiveness of this technique. Some simple theoretical modelling has been also developed.