Coarsening behaviour and interfacial structure of γ′ precipitates in Co-Al-W based superalloys

This work discusses the effects of alloying on the coarsening behaviour of the L12 ordered γ′ phase and the structure of the γ/γ′ interfaces in three Co-Al-W base superalloys aged at ∼90 °C below the respective solvus temperatures: Co-7Al-7W, Co-10Al-5W-2Ta and Co-7Al-7W-20Ni (at.%). The coarsening kinetics are adequately characterised by the classical Lifshitz-Slyozov-Wagner model for Ostwald ripening. Co-7Al-7W exhibited much slower coarsening...