Assessment of used turbine blades on and beneath the surface for product regeneration: Generation of a damage model based on reflection, geometry measurement and thermography

The repair of high value turbine blades of aero engines yields the opportunity of saving cost and to reduce the environmental impact of aviation [1]. The vital part of the repair process is the estimation of the part's condition. Based on product regeneration processes the precise geometry measurement and sensitive damage detection on the turbine blades contribute to the restoration of aerodynamically effective geometry as well as the internal structural integrity to ‘as new’ condition. For the identification of the faults and deviations from the nominal condition sensors are needed that have a suitable resolution and use a approriate physical principal. Microcracks or small dents in the filigree geometry can lead to an early functional failure. The inspection time can be shortened through the multiscale approach by using fast sensors and optics with wider view angles for the detection of hints for defects. The evaluation of the hints occurs afterwards with accurate, high resolution sensors and optics, which have longer measurement time per surface area.