Insight into the anisotropic electrochemical corrosion behaviors of laser metal deposited Ni-based single crystal superalloy

Aiming to marine environment for Ni-based single crystal superalloy, whether anisotropy affects the electro-chemical corrosion behavior of laser metal deposited component is unclear. This work reveals that the corrosion resistances increase in the order of (001) < (111) < (011), agrees well with the sequence of film thickness. The passive films are mainly composed of W6+, Ta5+, Al3+, and Mo6+ oxides. The optimal performance of (011) surface is attributed to the thickest film and the highest fractions of W6+ and Al3+ oxides. Our results pave the way for the orientation design of laser repaired superalloys to acquire optimal corrosion properties.

Automated summary

It is unknown whether anisotropy affects the electro-chemical corrosion behavior of Ni-based single crystal superalloy in marine environment. This study reveals that the corrosion resistance increases in the order of (001) < (111) < (011), which is consistent with the sequence of film thickness. The passive films mainly contain W6+, Ta5+, Al3+, and Mo6+ oxides. The optimal performance of (011) surface is due to the thickest film and the highest fractions of W6+ and Al3+ oxides. These findings pave the way for orientation design of laser repaired superalloys to achieve optimal corrosion properties.