Epitaxial repair and in situ damage assessment for turbine blades

Abstract

For single crystal components a technology to repair tips by epitaxial laser cladding was studied, to verify if, with a Nd-YAG laser, improved deposit efficiencies can be obtained with respect to published data relative to a CO2 laser. A user-friendly software tool was developed to make experiments and process development easier. With the support of this tool deposit efficiencies 1.5-times higher were reached. In the field of non-destructive technologies a frequency scanning eddy current technique named F-SECT was developed by CESI able to assess the damage degree of MCrAlY coatings due to operation. A recent improvement of this technique applicable in situ, on mounted blades in the turbine, will be described.