Precipitation of -NiAl phase in a high Ru-containing Ni-based single crystal superalloy

The precipitation of beta-NiAl phase in a high Ru-containing Ni-based single crystal superalloys was investigated. The beta-NiAl phase is mainly distributed in the interdendritic region of the as-cast structure. And it was found parts of Ru elements were polarized in beta-NiAl phase as the existence of strong bonds between Ru atoms and Al atoms. In addition, the solidification path of the experimental alloy passes through the region of the L -> L-1 + gamma -> L-2 + gamma + beta-NiAl -> L-3 + gamma + beta-NiAl + precipitated gamma ' -> gamma + beta-NiAl + precipitated gamma ' + gamma/gamma ' eutectics. It provides experimental data and theoretical guidance for the composition design of the novel Ru-containing high-generation Ni-SCs.