Thermography of the cooling channels using steam heating

The thermography inspection is the most modern non-destructive test method that has been expanding in the industry in recent years. There are several benefits such as high-speed testing, along with high precision and the ability to inspect without conduct. The advantages of this method, which leads to lower costs and increase accuracy in testing, make us able to use this method to detect the defects in the gas turbine blade channels to increase the accuracy of the fault diagnosis and it reduces the maintenance costs. Gas turbines have many uses in the industry. The efficiency of these turbines increases with increasing combustion temperature. The goal is to achieve more efficiency, but there are limitations to this goal. When shape of cooling channels has a complex geometric shape, maybe the ceramic muscle cannot completely exit at the casting stage and it will break. Remaining these particles in the cooling channels can seriously affect the turbine performance. So it's very important to detect this defect before using a defective blade. In this paper, it was aimed to detect existed channels in the workpiece to examine the effect of injected vapor pressure into the channels as temperature stimulus and to investigate the influence of channel distance from the surface from the results obtained by thermography.