Rapid Detection of Cracks in Turbine Blades Using Ultrasonic Infrared Thermography

Ultrasonic infrared thermography was used to detect the crack in the turbine blades in this work. In order to explore the effect of couplant on the detection results, three groups of comparative test were carried out respectively by using no couplant, sheet metal and medical adhesive plaster as couplant. On this basis, infrared image sequences and temperature data were analyzed. The results obtained show that couplant is the key factor to the detection efficiency of ultrasonic infrared thermography, and the medical adhesive plaster is a type of better couplant compared to the sheet metal. Additionally, ultrasonic infrared thermography can effectively detect the crack in the blade with the detection time of 1s, which demonstrates that the ultrasonic infrared thermography is very suitable for the situation of rapid detection. (paper)