Ultrasound lock-in thermography as a quantitative technique for quality control assessment of cast iron turbocharger components

This paper explores the application of ultrasound activated infrared thermography for the detection and quantification of flaws in industrial cast iron turbocharger components. The use of amplitude modulated ultrasonic heat generation allowed selective response of defected area, since the defect itself is turned into a local thermal wave emitter. Due to the very fast cycle time (< 30 s/part), the method could potentially be applied for 100% quality control of cast parts. After a brief description of the measurement technique and experimental setup used to carry out the tests, main results and discussion are reported. Most emphasis has been addressed to assess the influence of different operative parameters on defect’s detection capability as well as accurate sizing of the discontinuity.