TY - JOUR
T1 - Investigation of the slip geometry of high-purity potassium by in situ X-ray diffraction
AU - Krystian, Maciej
AU - Pichl, Wolfgang
N1 - Zeitschrift: Materials Science and Engineering A
DOI: 10.1016/j.msea.2004.02.082
Affiliations: Institute for Materials Physics, University of Vienna, Strudlhofgasse 4, Boltzmanngasse 5, A-1090 Vienna, Austria
Adressen: Pichl, W.; Institute for Materials Physics; University of Vienna; Strudlhofgasse 4, Boltzmanngasse 5 A-1090 Vienna, Austria; email: [email protected]
Import aus Scopus: 2-s2.0-10444278166
04.12.2007: Datenanforderung 2001 (Import Sachbearbeiter)
PY - 2004
Y1 - 2004
N2 - Plastic deformation of bcc metals at intermediate and low temperatures is dominated by [1 1 1] screw dislocations which macroscopically seem to glide on planes of high or irrational Miller indices. It is now well established that this non-crystallographic glide is composed of elementary steps of kink-pair formation on three symmetry-equivalent low-index planes. In the present investigation, the slip geometry of high-purity potassium single crystals was investigated by in situ X-ray measurements of the lattice rotation in uniaxial compression in the temperature range from 6 to 70 K. The different alternatives for the elementary glide planes, e.g., {1 1 0}, {2 1 1} or {3 2 1}, can be uniquely distinguished from changes of the primary slip direction within the unit triangle. The results showed that the elementary glide step in potassium occurs on {2 1 1} planes in the investigated temperature range. In addition, glide of [1 0 0] dislocations (obviously products from interactions between mobile and sessile [1 1 1] dislocations) becomes dominating in many samples at increasing plastic strain. Numerical simulations of the orientation change in ?1 1 1?{2 1 1} glide, based on the model of thermally activated kink-pair formation, were in good agreement with the experimental results. Π2004 Elsevier B.V. All rights reserved.
AB - Plastic deformation of bcc metals at intermediate and low temperatures is dominated by [1 1 1] screw dislocations which macroscopically seem to glide on planes of high or irrational Miller indices. It is now well established that this non-crystallographic glide is composed of elementary steps of kink-pair formation on three symmetry-equivalent low-index planes. In the present investigation, the slip geometry of high-purity potassium single crystals was investigated by in situ X-ray measurements of the lattice rotation in uniaxial compression in the temperature range from 6 to 70 K. The different alternatives for the elementary glide planes, e.g., {1 1 0}, {2 1 1} or {3 2 1}, can be uniquely distinguished from changes of the primary slip direction within the unit triangle. The results showed that the elementary glide step in potassium occurs on {2 1 1} planes in the investigated temperature range. In addition, glide of [1 0 0] dislocations (obviously products from interactions between mobile and sessile [1 1 1] dislocations) becomes dominating in many samples at increasing plastic strain. Numerical simulations of the orientation change in ?1 1 1?{2 1 1} glide, based on the model of thermally activated kink-pair formation, were in good agreement with the experimental results. Π2004 Elsevier B.V. All rights reserved.
U2 - 10.1016/j.msea.2004.02.082
DO - 10.1016/j.msea.2004.02.082
M3 - Article
SN - 0921-5093
VL - 387-389
SP - 115
EP - 120
JO - Materials Science and Engineering A: Structural Materials: Properties, Microstructures and Processing
JF - Materials Science and Engineering A: Structural Materials: Properties, Microstructures and Processing
IS - 1-2 SPEC.
ER -