The elemental partitioning characteristics of Ru additions within the microstructure of high refractory content Ni-base single crystal superalloys have been investigated using atom probe tomography (APT). Although detailed microanalysis revealed some dissolution of Ru within the ordered intermetallic γ′ precipitates, Ru was observed to preferentially partition to the disordered γ matrix. The partitioning characteristics of two nominally similar alloys with and without Ru were studied as part of this investigation. Analyses indicate that no significant changes in the partitioning characteristics of the constituent elements could be attributed to the presence of Ru for this particular set of alloys. The preferential site occupancy of Ru within the L1 2 lattice was also statistically quantified using ALCHEMI (atomic site location by channelling enhanced microanalysis). Interestingly, Ru exhibited a tendency to substitute for Al and occupy the corner sites in the γ′ structure.
Several effects of platinum group metal (PGM) additions to Nibase alloys were investigated using a transmission electron microscope (TEM). An experimental Re-containing alloy, Cantab17 (C17), was designed to reflect current third generation single crystal superalloys. Various levels of Ru, Rh, Ir, Pd and Pt were then systematically added to investigate the effects of these alloying elements. In addition to this, ternary Ni-19at%Al-3at%PGM alloys were investigated. / ' phase partitioning ratios determined through TEM-EDS showed that for the C17-based alloys, Ru was the only PGM to partition to , while elevated levels of Rh, Ir, Pd and Pt were observed to reside within the ' phase. Atomic site location (Al site or Ni site) of the PGMs in Ni 3 Al were found through ALCHEMI (atomic site location by channelling enhanced microanalysis) on the ternary Ni-Al-PGM alloys. Results showed that Ru preferentially partitions to Al sites with the other PGMs invariably showing some preference for Ni sites. Finally, a mechanism is proposed to explain the correlation between / ' phase partitioning and ' atomic site location of the PGMs in advanced superalloys.
6) were structurally and computationally analyzed. Weak intramolecular interactions were found to play the main role in determining the most favorable structure of the free ligands, therefore controlling the final coordination mode, and the nuclearity of the complexes. Further information on the nature of the intra-and intermolecular interactions were provided utilizing computational density functional theory calculations and topological charge density analysis according to the Quantum Theory of Atoms in Molecules. The efficient control of the structure of the complexes also results in a better control of the material properties.
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