About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
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Symposium
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Deformation and Damage Mechanisms of High Temperature Alloys
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Presentation Title |
Systematic Study of the Effect of Alloying on APB and SISF Energies in L12-(Co,Ni)3(Al,W,Ta) |
Author(s) |
K V Vamsi, Tresa M Pollock |
On-Site Speaker (Planned) |
K V Vamsi |
Abstract Scope |
The presence of ordered γ′ (L12) results in various precipitate shearing modes involving planar faults in Ni-, Ni-Co and Co-base superalloys. Planar fault energies (PFEs) are sensitive to the composition of the precipitate and thereby results in unique deformation mechanisms. Antiphase boundary (APB) coupled shear and stacking fault ribbons involving both APB and superlattice intrinsic stacking faults (SISFs) are often reported in CoNi-base superalloys. Additionally, microstructural characterization reveals a certain degree of chemical segregation in the vicinity of the planar faults. Given the importance of planar defects and the lack of knowledge of planar fault energies in CoNi-base superalloy compositions, the present work employs a novel diffuse multi-layer fault (DMLF) model to calculate APB and SISF energies using proximate γa', D024, structures as approximations to APB and SISF. The PFEs in (Co,Ni)3(Al,W,Ta) are evaluated using first-principles calculations, and the implications for alloy design will be discussed. |
Proceedings Inclusion? |
Planned: |
Keywords |
High-Temperature Materials, Other, Modeling and Simulation |