About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
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Advances in the State-of-the-Art of High Temperature Alloys
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Presentation Title |
Rafting Behavior of Single Crystal Ni-based Superalloys After Laser Peening: Insights and Implications |
Author(s) |
Noah Holtham, Keivan Davami |
On-Site Speaker (Planned) |
Noah Holtham |
Abstract Scope |
Single-crystalline Ni-based superalloys such as CMSX-4 are prone to directional coarsening, or rafting, under uniaxial thermo-mechanical loads. Though rafting has been studied for years, the focus has largely been on bulk material coarsening in the context of creep. Here, the localized rafting behavior at the surface of CMSX-4 following laser peening (LP) was explored using advanced microscopy and mechanical testing techniques. It was found that LP and subsequent 1100°C/100-hour thermal exposure encourages the formation of rafts near the LPed surface but are highly dependent upon the direction of residual stresses and density of dislocations. Dislocations from LP aided in the mass transport of γ-stabilizing elements and altered the interface mobility of γ’ into γ. Additionally, the superposition of residual and misfit stresses was found to have a strong influence on raft directionality. Lastly, rafts were localized to within 3mm from the LP surface with non-directional coarsening occurring at greater depths. |
Proceedings Inclusion? |
Planned: |
Keywords |
Copper / Nickel / Cobalt, Surface Modification and Coatings, Characterization |