Precipitation of Topologically Close Packed Phases in Ni-base Superalloys – the Effect of Re and Ru

The high-temperature strength of Ni-base superalloys may be strongly improved by alloying with Re. On the other hand, addition of Re has a negative influence on the long-term high-temperature stability - it leads to precipitation of topologically close packed phases. These phases, in turn, are detrimental for the high-temperature strength of Ni-base superalloys. Their precipitation process may be suppressed by alloying with Ru. Physical phenomena controlling this behavior are described in this work bringing the new insight into understanding of the Re- and Ru effect on precipitation of topologically close packed phases.