Post by
ScandiumPower on Feb 06, 2024 3:15am
Scandium addition improves properties of Titanium alloy
Improving thermal stability and creep resistance by Sc addition in near-α high-temperature titanium alloy
Scandium additions of 0.5 % making clear effect on titanoim alloy properties
''Conclusions
The near-α Ti-6.5A1–2.5Sn-9Zr-0.5Mo-1Nb-1W-0.3Si alloys with different content of Sc were prepared for aerospace applications. The mechanical properties of alloys before and after thermal exposure and creep resistance were investigated, and the effect of Sc on the microstructure and thermal stability was systematically analyzed. The main conclusions are summarized below:
(1)Sc refines the lamellar secondary α phase, the formation of Sc2O3 improves the strength, while excessive Sc2O3 becomes the crack source in the tensile process, which deteriorates the plasticity of the alloy.
(2)The oxygen content in the matrix is reduced with the Sc addition, which inhibits the growth of the Ti3Al phase and slows down alloy plasticity loss. The thermal stability of the alloy is improved.
(3)Sc improves the dispersion of primary silicides. Also, it accelerates the precipitation of silicides in the α/β phase boundary of the titanium alloys during creep.
(4)The refined lamellar secondary α phases, Sc2O3 particles, Ti3Al phase, and silicides together contribute to the enhancement of creep resistance for the Sc-containing alloy, especially the silicides precipitation exhibits a strong effect in preventing dislocation movement.''
https://www.sciencedirect.com/science/article/pii/S1005030223009362