About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
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High Temperature Creep Properties of Advanced Structural Materials
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Presentation Title |
Induction of Alternative Shearing Pathways during Creep Deformation of Nickel Based Superalloys via Local Phase Transformation Strengthening |
Author(s) |
Ashton J. Egan, Fei Xue, Emmanuelle Marquis, Michael J Mills |
On-Site Speaker (Planned) |
Ashton J. Egan |
Abstract Scope |
Deformation of nickel-based superalloys during intermediate temperature creep is dominated by planar defects and microtwinning, where shearing processes are controlled by diffusion mediated segregation and reordering. Local Phase Transformation (LPT) strengthens alloys via formation of η/χ at the defects. Novel LPT strengthening has recently been shown along microtwin boundaries through correlative controlled Electron Channeling Contrast Imaging (cECCI) and Scanning Transmission Electron Microscopy (STEM) studies. This LPT obstructs additional shearing partial dislocations from thickening microtwins, thus preventing rapid strain accumulation. In response, strain alternatively accumulates via deformation induced formation of ordered-HCP “nano-laths”; these are associated and grow from LPT at microtwin interfaces and appear formed by otherwise twin-inducing partials. Advanced characterization of deformation processes was conducted utilizing cECCI, probe corrected STEM, and atomic resolution Energy Dispersive X-Ray Spectroscopy (EDS) to confirm lattice site occupancies. |
Proceedings Inclusion? |
Planned: |
Keywords |
Characterization, High-Temperature Materials, Phase Transformations |