Sessile dislocations by reactions in NiAl severely deformed at room temperature
- Author(s)
- D. Geist, C. Gammer, C. Rentenberger, H. P. Karnthaler
- Abstract
B2 ordered NiAl is known for its poor room temperature (RT) ductility; failure occurs in a brittle like manner even in ductile single crystals deforming by single slip. In the present study NiAl was severely deformed at RT using the method of high pressure torsion (HPT) enabling the hitherto impossible investigation of multiple slip deformation. Methods of transmission electron microscopy were used to analyze the dislocations formed by the plastic deformation showing that as expected dislocations with Burgers vector a <1 0 0 > carry the plasticity during HPT deformation at RT. In addition, we observe that they often form a <1 1 0 > dislocations by dislocation reactions; the a <1 1 0 > dislocations are considered to be sessile based on calculations found in the literature. It is therefore concluded that the frequently encountered 3D dislocation networks containing sessile a <1 1 0 > dislocations are pinned and lead to deformation-induced embrittlement. In spite of the severe deformation, the chemical order remains unchanged.
- Organisation(s)
- Physics of Nanostructured Materials
- External organisation(s)
- Lawrence Berkeley National Laboratory
- Journal
- Journal of Alloys and Compounds
- Volume
- 621
- Pages
- 371-377
- No. of pages
- 7
- ISSN
- 0925-8388
- DOI
- https://doi.org/10.1016/j.jallcom.2014.09.226
- Publication date
- 02-2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103042 Electron microscopy, 103018 Materials physics, 210004 Nanomaterials
- Keywords
- ASJC Scopus subject areas
- Mechanics of Materials, Mechanical Engineering, Metals and Alloys, Materials Chemistry
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/sessile-dislocations-by-reactions-in-nial-severely-deformed-at-room-temperature(3846d5ee-05d8-41d8-8f51-80a69c134618).html