Effect of Ti and Al Contents on γ′ Morphology in Wrought Ni-based Superalloys

The effect of the content of Ti and Al on the morphology of gamma' precipitates is examined for 13 kinds of Ni. based model alloys aged at 1073 K/100 h. The morphology of gamma' precipitates was evaluated using the absolute moment invariants technique. The magnitude of cuboidal for gamma' particles clearly depends on the lattice misfit, but does not depend on the volume fraction of the particles. More gamma' particles tend to form a flat and parallel interface pair or elongated shape when the Ti and Al content is increased. These results suggest that the lattice misfit makes gamma' particles cuboidal and volume fraction strengthens their interaction, leading to a unique morphology.