|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Materials for High Temperature Applications: Next Generation Superalloys and Beyond
||ICME Approach to Design γ'/γ'' Composite Precipitate Microstructure for Ni-based IN718 Super Alloys
||Rongpei Shi, Donald McAllister, Ning Zhou, Andrew Detor, Richard DiDomizio, Sanket Sarkar, Michael Mills, Yunzhi Wang
|On-Site Speaker (Planned)
A new, high performance heavy duty gas turbine wheel material capable of operating at 1200℉ and above is desired to increase combined cycle turbine efficiency for the next-generation advanced cycle. As such, a new alloy design strategy is being explored to achieve the goal through microstructure stability control via γ'⁄γ" co-precipitation. By linking directly to CALPHAD thermodynamic and kinetic databases, as well as a generalized nearest-neighbor broken-bond prediction of interfacial energies, a quantitative multi-phase field model is developed to study the co-precipitation behaviors of γ' and γ" phases in the conventional and modified IN718 nickel-based superalloy. The influence of alloy chemistry and heat treatment conditions on the precipitation sequence and thus the co-precipitation behavior of composite γ'⁄γ" particles with different morphologies will be addressed.