|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys II
||Thermodynamic Database for the Co-Al-W-Ni-Ti-Ta-Cr Superalloy System
||Peisheng Wang, Wei Xiong, Oleg Kontsevoi, Ursula R. Kattner, Carelyn E. Campbell, Eric Lass, Gregory B Olson
|On-Site Speaker (Planned)
Co-base alloys attract attention due to their high solvus temperature, superior hot corrosion resistance, better weldability and thermal fatigue resistance compared to Ni-based superalloys. Limiting the application of traditional Co-based alloys is the low strength at high temperatures. In our previous work, we performed a comprehensive CALPHAD assessment of the Co-Al-W system. The ternary gamma’ phase was described as a metastable phase utilizing results from density functional theory (DFT) calculations. To stabilize the gamma’ phase and improve the properties of the Co-Al-W based superalloys, additional components (Ni, Ti, Ta, Cr) are added. In the present work, a thermodynamic database for the Co-Al-W-Ni-Ti-Ta-Cr superalloy system is constructed, aiming to include all binaries, key ternary (including but not limited to Co-Al-X, Co-W-X), and important quaternary systems. Comparisons between the calculated results and experimental data for various multi-component Co-Al-W-X based superalloys are made demonstrating the fidelity of the new Co superalloy database.