Development Of A Total-area Scanning Photoluminescence Piezo-spectroscopy System For TGO Residual Stress Measurement On Turbine Blades

Thermal barrier coatings(TBCs)are used on the high-temperature parts of turbine engines to protect the substrate and increase the operating temperature of the turbine engine.During the service process of thermal barrier coating,Thermal mismatch stress and thermal growth stress usually concentrate on thermal grown oxide(TGO)layer.The accumulation of internal stress in thermal barrier coating provides driving force for the generation,expansion and coalescence of cracks,resulting in coating failure and spalling.In other words,the TGO layer is the most vulnerable area for TBCs to fail.Therefore,the distribution of TGO residual stress is an important and direct basis for judging the overall quality and service life of thermal barrier coatings on turbine blades,and it is an urgent practical demand to realize the scientific and effective evaluation of the service condition of turbine blades.With this key technical deficiency in-mind,the proposed application intends to develop a new type of “total-area scanning photoluminescence piezo-spectroscopy system for TGO residual stress measurement on curved surface of turbine blades”,and simulated the operation of the equipment through Blender software to provide guidance for the equipment construction.Finally,the TGO residual stress distribution nephogram was drawn for the thermal barrier coating samples of turbine blade structure to complete the experimental verification of the equipment.The main research contents of this paper are as follows:(1)Referred to the current development ideas of photostimulated luminescence piezo-spectroscopy(PLPS)equipment,the construction ideas of PLPS equipment were determined.The key engineering problems in the construction of total-area scanning PLPS system are extracted,and the design of each module of the total-area scanning PLPS systemt is completed.(2)To model the total-area scanning PLPS systemt in Blender software,and to simulate the total-area scanning detection method of PLPS device to find the best way.Finally,the PLPS total-area scanning detection device was simulated in Blender software to analyze the influence of the test results of equipment working parameters.(3)The ceramic layer of turbine blade sample was prepared by electron beam vapor deposition(EB-PVD),and the influence of sample substrate curvature on the columnar crystal growth orientation of the ceramic layer was analyzed by SEM.The TGO residual stress of turbine blade samples was tested by the total-area scanning PLPS system to map the distribution of TGO residual stress distribution and verifiy the feasibility of the system.