About this Abstract |
| Meeting |
2022 TMS Annual Meeting & Exhibition
|
| Symposium
|
Grain Boundaries and Interfaces: Metastability, Disorder, and Non-Equilibrium Behavior
|
| Presentation Title |
Deformation of Lamellar FCC-B2 Nanostructures Containing Kurdjumov-Sachs Interfaces: Relation between Interfacial Structure and Plasticity |
| Author(s) |
Deep Choudhuri |
| On-Site Speaker (Planned) |
Deep Choudhuri |
| Abstract Scope |
By coupling high-resolution transmission-electron-microscopy and molecular dynamics (MD) simulations we have investigated the deformation mechanisms prevalent in lamellar micro- structures containing soft fcc and hard bcc-ordered intermetallic B2, whose interfaces follow the Kurdjumov-Sachs (KS) orientation relationship. TEM/MD coupling indicated that the KS interface contained steps and ledges, with several steps exhibiting fcc-B2 lattice continuity between the {111}fcc and {011}B2. The KS-fcc (111) interfacial plane also contained periodically arranged 1/6<112>fcc partial dislocations with screw-like character, which were separated by extended dislocation “core-overlap” regions. We observed that the screw-like interfacial partials facilitated the KS interfacial sliding and strain accumulation at the interphase interfaces and reduced the yield strength of the composite material compared to a pure-fcc reference material. Deformation character also depended on B2 lamellae thickness: thinner B2 lamellae sheared via twinning to drastically lowered flow stress such that the flow-strength, while thicker B2 lamellae sheared via a slip-transfer mechanism. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, Thin Films and Interfaces, Copper / Nickel / Cobalt |