Contributions of atom probe tomography to the understanding of nickel-based superalloys

Atom probe tomography enables atomic level microstructural characterization to be performed on complex engineering materials such as superalloys. The technique provides information on the size, morphology and compositions of coexisting phases, the solute partitioning of the elements between the phas es, and solute segregation to interfaces and grain boundaries. This informa tion leads to a more complete understanding of nickel-based superalloys. Th e types of atomic level information that may be obtained with atom probe to mography are illustrated with examples of the formation of fine gamma preci pitates within the central region of the gamma' phase in PW 1480, the evolu tion of the dual gamma'/gamma " nature of secondary precipitates in alloy 7 18, the interphase precipitation of the gamma' phase at the primary gamma " -gamma interface in alloy 718, and the quantification of the level and spat ial extent of the boron segregation at grain boundaries in a nickel-molybde num superalloy. Published by Elsevier Science Ltd.