Microstructural characterization of laser welding repair ofdirectionally solidified GTD-۱۱۱ nickel-based superalloy

Wire-based laser metal deposition (WBLMD) is one of the most promisingmethods for the build-up and repair of the damaged nickel-based superalloys componentsused in the hot-section of gas turbine engines, in order to extend their lifetime and improvethe reliability. In the current study, welding repair of a directionally solidified nickel-basedsuperalloy with a solid solution nickel-based superalloy filler metal, IN۶۲۵, was investigated.After parameters optimization, microstructural evaluations were carried out by optical andscanning electron microscope. Based on the microstructural evaluation, the built-upmicrostructure contains of the cellular and dendritic regions, while the interface of base metaland weld metal governs an epitaxial growth regime. The obtained results showed thatporosity and microcracks have not been observed, after parameter optimizations

کلیدواژه ها:

directionally solidified GTD-۱۱۱ ، Laser welding ، microstructure ، Liquationcracking ، dendritic structure