Competing accommodation mechanisms of the martensite in nanocrystalline NiTi shape memory alloys
- Author(s)
- Thomas Waitz, Wolfgang Pranger, Thomas Antretter, Franz Dieter Fischer, Hans-Peter Karnthaler
- Abstract
Two competing mechanisms that compensate the transformation strains of the martensite are observed by transmission electron microscopy studies of nanocrystalline NiTi alloys. A single variant of compound twinned martensite forms below a critical grain size of about 100nm. In larger grains, a herringbone morphology of two different twinned variants of the martensite is observed. Calculations show that homogeneous transformation strains are reduced by the self-accommodating arrangement of different martensitic variants. This takes place at the expense of the formation of additional interfaces causing local strain concentrations. It is concluded that the size dependence of the martensitic morphology is caused by a different scaling behavior of the homogeneous and interfacial strain energies.
- Organisation(s)
- Physics of Nanostructured Materials
- External organisation(s)
- Montanuniversität Leoben
- Journal
- Materials Science and Engineering A: Structural Materials: Properties, Microstructures and Processing
- Volume
- 481-482
- Pages
- 479-483
- No. of pages
- 5
- ISSN
- 0921-5093
- DOI
- https://doi.org/10.1016/j.msea.2007.03.122
- Publication date
- 2008
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103018 Materials physics
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/4d009fc0-9399-4d7d-9140-dc3a10c3eec9