Sessile dislocations by reactions in NiAl severely deformed at room temperature

Autor(en)

D. Geist, C. Gammer, C. Rentenberger, H. P. Karnthaler

Abstrakt

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(en)

Physik Nanostrukturierter Materialien

Externe Organisation(en)

Lawrence Berkeley National Laboratory

Journal

Journal of Alloys and Compounds

Band

621

Seiten

371-377

Anzahl der Seiten

7

ISSN

0925-8388

DOI

https://doi.org/10.1016/j.jallcom.2014.09.226

Publikationsdatum

02-2015

Peer-reviewed

Ja

ÖFOS 2012

103042 Elektronenmikroskopie, 103018 Materialphysik, 210004 Nanomaterialien

Schlagwörter

ASJC Scopus Sachgebiete

Mechanics of Materials, Mechanical Engineering, Metals and Alloys, Materials Chemistry

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/3846d5ee-05d8-41d8-8f51-80a69c134618