Role of Ru on the microstructure and property of novel Co-Ti-V Superalloy

In the present paper, the authors investigated the microstructures and mechanical properties of dual-phase Co-Ti-V-based superalloys with different additions of Ru. The results showed that with the increase of Ru contents, the size of gamma ' precipitates of the alloy gradually raised, the volume fraction of gamma ' phase slightly, and the lattice misfit between gamma/gamma ' phases increased. Ru was enriched in the gamma ' phase, and the elemental partition coefficients (K-X = C-gamma '/C-gamma) of Ti and V increased with the increment of Ru. The Ru contents have no remarkable influence on the solvus temperatures of gamma ' in the Co-Ti-V alloys. The yield strength at 1000 degrees C of the Co-10Ti-11V-0.5Ru alloy was the highest, while the yield strength of the 1Ru alloy was the smallest. Transmission electron microscopy and scanning electron microscopy observations showed that the gamma ' shape in the compressed specimen containing 0.5Ru remain integrated, while the gamma ' in other alloys were cut into several parts.