Abstract
The deformation carried by a twin is a simple shear like it is for a moving disclination dipole. This coincidence is the motivation for modeling twinning phenomena in terms of disclinations. A justification for disclination models is given for twins being blocked at strong barriers. Making use of the disclination dipole model, a twin intersection mechanism is presented and applied to various experimental observations. These comprise i) the rotation of the intersection prism (common volume of incident twin and barrier twin) in austenitic steel and its variation when a bundle of twins penetrate together, ii) the formation of a diamond hexagonal phase and stacking faults in the intersection prism in silicon and germanium and iii) the formation of secondary twins. In all these cases, a complex dislocation dynamics can be rationalized by a simple disclination approach. Implications to mechanical properties such as work hardening and fracture are outlined. Finally, various applications of the disclination model for twins like twinning in martensite and ferroelastic films are overviewed.
Original language | English |
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Pages (from-to) | 227-238 |
Number of pages | 12 |
Journal | Solid State Phenomena |
Volume | 87 |
DOIs | |
State | Published - 2002 |
Event | Proceedings of the International Workshop on Local Lattice Rotations and Disclinations in Microstructures of Distorted Crystalline Materials - Rauschenbach, Germany Duration: 10 Apr 2000 → 14 Apr 2000 |
Keywords
- Deformation Twinning
- Disclination Dipoles
- Dislocation Walls
- Fracture
- Hardening
- Secondary Twin
- Somigliana Dislocations
- Strength
- Twin Intersection