|About this Abstract
|10th International Symposium on Superalloy 718 and Derivatives (2023)
|Superalloy 718 and Derivatives
|Investigating Deformation Mechanisms in a Creep-deformed 718-variant Superalloy
|Semanti Mukhopadhyay, Hariharan Sriram, Richard DiDomizio, Andrew J. Detor, Robert Hayes, Yunzhi Wang, Michael J. Mills
|On-Site Speaker (Planned)
Improving the efficiency of a land-based industrial gas turbine ultimately relies on novel alloy development for the turbine wheel. However, this alloy development task is challenging because it necessitates higher temperature capabilities along with phase stability during low cooling rate processing of a full-scale wheel. These challenges make 718-based variant alloys an attractive choice because of their superior thermal stability. However, to develop these novel alloys, their deformation behavior must also be accounted for. Thus, in the present work, we investigate the microstructure and creep deformation behavior of a novel 718-variant alloy. Detailed microstructural characterization reveals that the phase fraction of the γ'' phase in the variant alloy is much lower than 718. In addition, the presence of Mo causes detrimental grain boundary precipitation which leads to final failure during tensile creep deformation. The variant alloy accumulates creep strain faster than 718, ultimately fracturing at 0.6% strain. Finally, a detailed characterization of the deformed variant alloy reveals extensive microtwinning.
|Definite: At-meeting proceedings