NANOSYSTEMS: PHYSICS, CHEMISTRY, MATHEMATICS, 2014, 5 (4), P. 486-493
AB-INITIO STUDY OF Re AND Ru EFFECT ON STABILITY OF TCP NANOPARTICLES IN Ni-BASED SUPERALLOYS
N. I. Medvedeva – Institute of Solid State Chemistry UB RAS, Ekaterinburg, Russia; email@example.com
A. L. Ivanovskii – Institute of Solid State Chemistry UB RAS, Ekaterinburg, Russia
Modern nickel-based superalloys contain high concentrations of rhenium that allows the improvement of their creep strength. The high levels of rhenium, however, results in the formation of topologically close-packed phases (TCP) which have a negative influence on its properties. The addition of ruthenium was found to reduce the precipitation of nano-sized TCP phases, but the reasons have not been established. In this paper, by using an ab-initio approach, we studied the effect of rhenium and ruthenium on the structural properties of Ni matrix as well as the TCP phases. We demonstrate that Cr, Mo and W are the most effective additions to provoke the formation of TCP phases, whereas ruthenium has a destabilizing effect.
Keywords: Ab initio calculations, rhenium effect, superalloys.
PACS 71.15.Mb 71.15.Nc 71.20.Be