Investigation on Grain Size Changes in Gamma Prime Precipitate on Varying Surface Location of IN738 Engine Turbine Blade

A used nickel based gas turbine blade was received and it has been previously operated
for more than 52000 hours and exposed to temperature approximately 720°C. The main
purpose of this project is to investigate the grain size changes in gamma prime
precipitate and to identify other different phases that occurred due to the high heat
exposure. A few different locations of the turbine blade have undergone SEM to obtain
the SEM images for grain size measurement and also EDX the to obtain the elemental
analysis. It is found that the grain size of gamma prime precipitate varies throughout the
surface of the turbine blade and there is a significant difference between the leading
edge and the trailing edge. There are also different types of phases present at the
microstructure of the blade due to extreme exposure to the turbine blade.