About this Abstract |
Meeting |
Superalloys 2021
|
Symposium
|
Superalloys 2021
|
Presentation Title |
The Effect of Alloying on the Thermophysical and Mechanical Properties of Co–Ti–Cr-Based Superalloys |
Author(s) |
Christopher H. Zenk, Nicklas Volz, Andreas Bezold, Laura-Kristin Huber, Yolita Eggeler, Erdmann Spiecker, Mathias Göken, Steffen Neumeier |
On-Site Speaker (Planned) |
Andreas Bezold |
Abstract Scope |
The system Co–Ti–Cr was recently identified as a very promising base for low mass-density Co-based superalloys. This study presents the influence of quaternary alloying additions on the thermo-physical and mechanical properties of a Co–11Ti–15Cr model superalloy. Al, Ta, Re and W were selected as a starting point for alloy development as they represent important alloying elements in both Ni-based and Co–Al–W-based superalloys. Microstructure analysis reveals that the addition of only 1 at.% of either of these elements causes the formation of different undesired intermetallic phases in addition to ã and ã′ phases, which is in agreement with thermodynamic calculations. However, a diffusion-couple between the Co–Ti–Cr and a Co–Al–W–Ta alloy suggests that the tolerance for alloying elements without destabilizing the ã/ã′ two-phase microstructure is higher when they are present in a certain ratio. Energy-dispersive X-ray spectroscopy shows that Cr and Re are enriched in the ã phase whereas Ti and W preferentially partition to ã′. All alloying elements increase the yield strength at room temperature, but are disadvantageous at 1000 °C. Re and W retain their strengthening effect up to 900 °C. |
Proceedings Inclusion? |
Undecided |