Characterization of Gamma Prime Phase in Hafnium Doped IN-738LC Nickel Base Superalloy

In this article, effect of hafnium (Hf) addition to IN-738LC nickel-base superalloy, on the morphology, size distribution and content of gamma prime (γ′) precipitate has been studied. Scanning electron microscopy employed for observation of γ′ precipitates in the matrix. Image analysis process has been performed by Clemex Image Analysis software (Clemex Technologies, Inc., 800 Guimond Blvd, Longueuil, Quebec, Canada). The results show that Hf addition increases the amount of γ′ phase in the alloy, change it morphology from cubical to irregular and spherical shape and forms more stable and finer γ′ particles. Furthermore, selection of a suitable heat treatment is very important for achievement to the obtained results.