Influence of Re/Ru on concentration distribution in the γ/γ′ phases of nickel-based single crystal superalloys

Publication date: 15 October 2017
Source:Materials & Design, Volume 132
Author(s): Delong Shu, Sugui Tian, Ning Tian, Lirong Liu, Shuang Liang, Baoshuai Zhang
In order to understand the influence of Ru and Re on the concentration distributions of elements in γ′ and γ phases, the partitioning behaviors of elements in various alloy are investigated by means of atom probe tomography (APT). Results show that the elements Al, Ta and Ni are enriched in γ′ phase, while the elements Co, Cr, Mo, W, Re and Ru are enriched in γ matrix phase. Adding Ru may decrease the partitioning ratio of elements in γ and γ′ phases. Wherein, when Ru atoms dissolve into γ′ phase to substitute the Al atoms, some Re, Mo and W atoms adhered in the round of Ru atoms, under the hybridization effect of d orbit, may dissolve into γ′ phase, which is thought to be the main reason of Ru decreasing the partitioning ratios of γ′ and γ phases. When adding Re into the alloy, the Re atoms with low diffusion coefficient may hinder the diffusion of other atoms away from γ′ phase during the growth of γ′ phase, which is thought to be the main reason of decreasing the partitioning ratios of elements in γ and γ′ phase.

Graphical abstract

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