Interaction of the Precipitation Kinetics of δ And γ’ Phases in Nickel-Base Superalloy ATI Allvac® 718PlusTM
In this paper, the precipitation behaviour of (Ni3(Nb,Al)) and ’ (Ni3(Al,Ti,Nb)) phases in the nickel-base superalloy ATI Allvac® 718PlusTM, as well as their kinetic interactions are discussed. Important parameters such as volume fraction, mean radius and number density of precipitates are experimentally determined and numerically simulated as a function of the heat treatment parameters time and temperature. To match the experimentally observed kinetics, the predicted interfacial energy of the precipitates, as calculated for a sharp, planar phase boundary, is adjusted to take into account the interfacial curvature and entropic effects of a diffuse interface. Correction functions for the interfacial energies of as well as ’ precipitates are presented. Using these modified interfacial energies, the calculated results show excellent agreement with the experimental measurements.
T. Chandra, N. Wanderka, W. Reimers , M. Ionescu
R. Radis et al., "Interaction of the Precipitation Kinetics of δ And γ’ Phases in Nickel-Base Superalloy ATI Allvac® 718PlusTM", Materials Science Forum, Vols. 638-642, pp. 2712-2717, 2010