| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Deformation and Transitions at Grain Boundaries VII
|
| Presentation Title |
Fatigue-induced Slip from Type II Twin Boundary Motion of Shape Memory Alloys |
| Author(s) |
Ahmedsameerkhan Mohammed, Huseyin Sehitoglu |
| On-Site Speaker (Planned) |
Ahmedsameerkhan Mohammed |
| Abstract Scope |
Shape Memory Alloys (SMAs) are technologically important functional materials with widening application domains from biomedical devices to soft-robotic actuators and space exploration rovers. The performance-limiting phenomenon of functional fatigue has mandated an understanding of fatigue-induced slip mechanisms. This study proposes the mechanism as a consequence of inhibited grain boundary motion during martensitic phase transformation in SMAs. The grain boundary is a Type II Twin Boundary (TB), common in these alloy systems. NiTi, the most successful SMA, is analyzed from an atomistic and topological modeling standpoint. The yet unknown interface structures for the TB and also the transformation habit plane are proposed and an emissary dislocation reaction is proposed in two stages. The first stage proposes a fault partial emission on the TB and the second stage proposes the interaction of the fault partial with the habit plane explaining the emission of a perfect slip dislocation into the austenite phase. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |