Ribs and Blades Evaluation

The laser ultrasonic beam has no side lobes that provides clear image of ribs failures. As well as this method allows to control the hard-to-reach areas of turbine blades and to detect micro-defects in these areas. For that purposes PLU-12U-02 transducer is developed. The difficulty of detecting a defect in the ribs with the traditional ultrasonic method is that the width of the probing beam is much larger than the rib itself. Thus a strong reflection of the ultrasonic signal from the bottom masks the reflection from the defect. Also traditional ultrasound has oscillations inside probe signal, which further masks the ultrasound signal from the defect. Laser ultrasound does not have this limitation because laser excites a single pulse. Scheme if ribbed panel laser ultrasonic evaluation are demonstrated below:

The results of single crystal blade laser ultrasonic evaluation are demonstrated below: