Intergrowth of P phase with mu phase in a Ru-containing single-crystal Ni-based superalloy

The precipitation of topologically close-packed (TCP) phases in a Ru-containing single-crystal Ni-based superalloy has been investigated. The high-angle annular dark field, selected area electron diffraction, and high-resolution transmission electron microscopy were used to analyze the TCP precipitates in this study. The intergrowth of P phase with m phase was found. This finding indicates that P phase may nucleate at stacking faults and subsequently grow at the expense of mu phase. The orientation relationship between P and mu phases was (1 0 0)(P)//(1 (1) over bar 1 2)(mu) and [0 1 (1) over bar](P)/[4 2 (1) over bar](mu).