Interplay of slip and twinning in niobium single crystals compressed\nat 77 K

0496930 - ÚFM 2019 RIV US eng J - Journal Article
Gröger, Roman - Chlup, Zdeněk - Kuběnová, Tereza - Kuběna, Ivo
Interplay of slip and twinning in niobium single crystals compressed
at 77 K.
Journal of Materials Research. Roč. 34, č. 2 (2019), s. 261-270. ISSN 0884-2914. E-ISSN 2044-5326
R&D Projects: GA ČR(CZ) GA16-13797S; GA MŠMT(CZ) LQ1601
Institutional support: RVO:68081723
Keywords : niobium * slip * twinning * 77 K * plasticity
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 2.502, year: 2019

High-purity niobium single crystals of five different orientations were compressed at 77 K to
2–4% plastic strain to investigate the mechanisms operative in the initial stage of yielding. The
crystals deformed in the direction close to the [001] axis exhibit predominant slip on the highstressed
(101) and a much lower stressed ð0 11Þ plane. The expected slip on the ð 101Þ plane is
nearly homogeneously distributed with only a few sharp slip traces corresponding to localized
slip. The samples compressed along center-triangle orientations and those close to the
½011 ½ 111 edge deform predominantly by twinning on {112}h111i systems with some
contribution from slip on the ð 101Þ½ 1 1 1 system with the highest Schmid factor. A majority of
twins exhibit internal contrast due to alternating slip on ð 101Þ and ð0 11Þ planes. No slip traces are
observed in the matrix adjacent to the twin, which implies that twin boundaries are impenetrable
obstacles for the motion of dislocations.
Permanent Link: http://hdl.handle.net/11104/0294008