|About this Abstract
||2020 TMS Annual Meeting & Exhibition
||Microstructural Template Consisting of a Face-Centered Cubic Matrix with Ordered Precipitates: Microstructural Evolution and Properties
||Coarsening and Creep Behavior of Co-Ni-Al-W-Ti-Ta-B Superalloy with High γ′ Solvus Temperature
||Fei Xue, Dingwen Chung, Eric Lass, David N Seidman, David C Dunand
|On-Site Speaker (Planned)
Increasing the γ′ solvus temperature of Co-base superalloys is an important challenge for their development and eventual commercial use. This work investigates two multinary Co-base alloys, with 0.5 at.% difference in Ti-content, which exhibit a high γ′ solvus temperature of 1196 and 1211°C. The γ-γ′ two-phase microstructure with ~80% γ′(L12) precipitates, observed in both alloys, coarsens slowly upon annealing at 900 and 1000°C for up to 1,000 h (and at 1100°C for up to 168 h), with the low Ti-content alloy showing a slightly less coarsened γ′ precipitates. No secondary phase precipitates are detected, even after the long-term annealing. Atom probe tomography shows enrichment of Ni, Al, W, Ti, Ta and B in the γ′ precipitates after annealing at 900°C for 168 h in both alloys. Comparable creep properties are found in both alloys at 850 and 900°C. A further composition design with Cr additions to these alloys is presented.
||Planned: Supplemental Proceedings volume