| The Ni-based superalloys have been widely used as turbine blades and aircraft engines due to their excellent high-temperature oxidation resistance as well as high creep strength.There are two primary phases in such alloys,?'phase and?matrix.Modern Ni-based superalloys ordinarily contain wide variety of alloying elements to enhance the high-temperature properties of each phase.The concentrations of refractory elements such as Cr,Mo,Re and W in the?phase tend to form TCP phases,which is detrimental to the high-temperature materials due to the depletion of solid solution strengthening elements.Some research results suggested that the addition of Ru could suppress the formation of TCP phases in superalloys by altering the partitioning behaviors of elements between the?and?'phase,but whether Ru actually causes the reverse is still a controversial issue.In this study,by using the first principle method,we firstly researched some properties of?'-Ni3Al,then studied the partitioning behaviors of refractory elements between the two phases and the influence of Ru addition on them.In addition,we analyzed the strengthening mechanism of Ru at the interface by differential charge density and partial wave density diagram.The lattice constant,cohesive energies,formation enthalpies and equilibrium concentration of point defect of Ni3Al were studied,the calculation results showed that:anti-site defects were easier formed than vacanty defects,and AlNi was the most important anti-site defect.Whether the Ru element can change the partitioning behaviors of refractory elements in the two phase of nickel based alloy is closely related to the concentration of Ru.The calculation results show that Cr,Mo,Re and W have a preference for the?matrix with the addition of one Ru atom?Ru 3.12 at%?,and the partition trend decreased.When two Ru atoms?Ru 6.25 at%?substitutes for the interface atoms,it is found reverse partitioning behaviors of Mo and Re. |
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