International Journal of Engineering and Technology

This paper presents the results of experimental investigation of thermal phenomena in a square shape (180 mm *180 mm) STS 304 specimen with 10 mm thickness and artificial defects with circular cut-outs of varying depth and diameter at the back side. The material is aimed to be tested by means of thermal wave thermography. Lock-in thermography is employed for the detection of defects. The temperature field of the front surface of material tested is observed and analysed. The four point correlation algorithms are applied to extract phase angle of thermal wave’s harmonic component. Phase image are analyzed to find the qualitative information about the defects. Phase contrast method was used for better identification and analysis of the existing defects of the specimen.