Zig-zag twins and helical phase transformations.
Philos Trans A Math Phys Eng Sci
; 374(2066)2016 Apr 28.
Article
em En
| MEDLINE
| ID: mdl-27002072
ABSTRACT
We demonstrate the large bending deformation induced by an array of permanent magnets (applied field â¼0.02 T) designed to minimize poles in the bent state of the crystal. Planar cantilevers of NiMnGa (5M modulated martensite) ferromagnetic shape memory alloy deform into an arched shape according to theory, with a zig-zag microstructure that complies with the kinematic and magnetic compatibility between adjacent twin variants. A general theory of bent and twisted states is given, applicable to both twinning and austenite/martensite transformations. Some of these configurations achieve order-of-magnitude amplification of rotation and axial strain. We investigate also atomistic analogues of these bent and twisted configurations with perfect interfaces between phases. These mechanisms of large deformation, induced by small magnetic fields or temperature changes, have potential application to the development of new actuation technologies for micro-robotic systems.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Philos Trans A Math Phys Eng Sci
Assunto da revista:
BIOFISICA
/
ENGENHARIA BIOMEDICA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos