TY - GEN
T1 - Numerical simulation of the simultaneous precipitation of δ and γ′ phases in the Ni-base superalloy ATI Allvac®718 Plus™
AU - Radis, Rene
AU - Zickler, Gerald A.
AU - Stockinger, Martin
AU - Sommitsch, Christof
AU - Kozeschnik, Ernst
PY - 2010/12/1
Y1 - 2010/12/1
N2 - The present work deals with the numerical simulation of the precipitation kinetics of δ (Ni3(Nb, Al)) and γ′ (Ni 3(Al, Ti, Nb)) phases in the commercial nickel-base superalloy ATI Allvac®718Plus™. Important precipitate parameters such as volume fraction, mean radius and number density are numerically calculated as a function of the heat treatment parameters time and temperature and compared to experimentally determined data. 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. Using these modified interfacial energies, the calculated results show excellent agreement with the experimental measurements. Finally, a calculated time-temperature-precipitation (TTP) diagram for concurrent δ and γ′ precipitation is presented, which clearly demonstrates strong kinetic interactions during simultaneous precipitation of these phases. Thus, the present study emphasizes the importance of carefully controlling the heat treatment parameters time and temperature during the production process of ATI Allvac®718Plus™, in order to achieve the desired microstructure and hence mechanical properties.
AB - The present work deals with the numerical simulation of the precipitation kinetics of δ (Ni3(Nb, Al)) and γ′ (Ni 3(Al, Ti, Nb)) phases in the commercial nickel-base superalloy ATI Allvac®718Plus™. Important precipitate parameters such as volume fraction, mean radius and number density are numerically calculated as a function of the heat treatment parameters time and temperature and compared to experimentally determined data. 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. Using these modified interfacial energies, the calculated results show excellent agreement with the experimental measurements. Finally, a calculated time-temperature-precipitation (TTP) diagram for concurrent δ and γ′ precipitation is presented, which clearly demonstrates strong kinetic interactions during simultaneous precipitation of these phases. Thus, the present study emphasizes the importance of carefully controlling the heat treatment parameters time and temperature during the production process of ATI Allvac®718Plus™, in order to achieve the desired microstructure and hence mechanical properties.
KW - ATI Allvac®718 plus™
KW - Delta
KW - Gamma prime
KW - Nickel-base superalloys
KW - Numerical simulations
KW - Precipitation kinetics
UR - http://www.scopus.com/inward/record.url?scp=79961013379&partnerID=8YFLogxK
M3 - Conference paper
AN - SCOPUS:79961013379
SN - 9781617827709
T3 - 7th International Symposium on Superalloy 718 and Derivatives 2010
SP - 569
EP - 578
BT - 7th International Symposium on Superalloy 718 and Derivatives 2010
T2 - 7th International Symposium on Superalloy 718 and Derivatives 2010
Y2 - 10 October 2010 through 13 October 2010
ER -