| Outline of data |
Five novel Co-30Ni-(6+x)Al-(3-y)W-yMo-1Ta-3.5Ti-12Cr-0.1Hf-0.025 C (x=0, y=0, 1, and x=2, y=0, 1,
2 at%) multi-component polycrystalline γ′-strengthened Co-base superalloys are designed to investigate the effects of Al and Mo content on the microstructure and properties in this study. Based on the 6Al3W alloy, the
addition of 2 at% Al has the effects of increasing the γ′ solvus temperature, reducing the density, increasing the γ′volume fraction and coarsening rate, reducing the Vickers hardness but increasing the yield strength at 750℃. The replacement of 1 at%W by 1 at% Mo remarkably reduced the density with a negligible effect on the γ′
coarsening rate; Meanwhile, this slightly reduced the γ′ solvus temperature and volume fraction causing a slight
decrease of Vickers hardness and yield strength at 750℃. The experimental alloys all show relatively low
density, large processing window, good microstructure stability at 750℃ and mechanical properties, especially
for 6Al2W1Mo alloy which has density of 8.69 g cm−3, processing window of 247℃, room-temperature Vickers
hardness of 5.1 GPa, stable microstructure without detrimental phase after a heat treatment of 900℃ @8 h
+750℃ @1000 h. These results may provide guidance for the development of the novel wrought Co-base
superalloys with high performance and low density. |
Last Update：August,23,2019 Created：August,23,2019
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February,13,2022
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