About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
|
Deformation and Damage Mechanisms of High Temperature Alloys
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Presentation Title |
The Effect of Environment on the Near-crack Deformation Induced during Dwell Fatigue of a Ni-base Superalloy |
Author(s) |
Zachary D. Harris, Philippa Reed, James Burns |
On-Site Speaker (Planned) |
Zachary D. Harris |
Abstract Scope |
The effect of environment on the near-crack deformation induced during dwell fatigue of low solvus, high refractory (LSHR) superalloy specimens was assessed using electron backscatter diffraction (EBSD)-based approaches. Dwell fatigue experiments completed at 725°C using a 1-90-1-1 trapezoidal waveform in laboratory air and vacuum (<0.05 Pa) were interrupted at a ΔK ≈ 40-44 MPam. Broad-scale EBSD was performed along the crack path, revealing that the magnitude and extent of deformation (quantified via kernel average misorientation) were systematically reduced for the specimen tested in vacuum. An evaluation of the geometrically necessary dislocation (GND) density in the crack-tip region was then conducted using cross-correlation-based high resolution EBSD, further underscoring the differences in near-crack deformation induced between the two environments. Results of this near-crack analysis are then evaluated in the context of the proposed role of crack tip oxidation on the dwell fatigue behavior of nickel-base superalloys. |
Proceedings Inclusion? |
Planned: |
Keywords |
Environmental Effects, Mechanical Properties, High-Temperature Materials |