Crystal Structure Defects in Titanium Nickelide after Abc Pressing at Lowered Temperature; Materials; Vol. 15, iss. 12

Bibliographic Details
Parent link:	Materials Vol. 15, iss. 12.— 2022.— [4298, 15 p.]
Corporate Author:	Национальный исследовательский Томский политехнический университет Инженерная школа ядерных технологий Отделение экспериментальной физики
Other Authors:	Lotkov A. I. Aleksandr Ivanovich, Grishkov V. N. Viktor Nikolaevich, Laptev R. S. Roman Sergeevich, Mironov Yu. P. Yury Petrovich, Zhapova D. Yu. Dorzhima Yurjevna, Girsova N. V. Nataljya Vasiljevna, Gusarenko A. A. Aleksandr Aleksandrovich, Barmina E. G. Elena Georgievna, Kashina O. N. Olga Nikolaevna
Summary:	Title screen The experimental results regarding the effect of warm (573 K) abc pressing with an increase in the specified true strain, e, up to 9.55, on the microstructure and crystal structure defects (dislocations, vacancies) of the Ti49.8Ni50.2 (at %) alloy are presented. It is shown that all samples (regardless of e) have a two-level microstructure. The grains-subgrains of the submicrocrystalline scale level are in the volumes of large grains. The average sizes of both large grains and subgrain grains decrease with increasing e to 9.55 (from 27 to 12 µm and from 0.36 to 0.13 µm, respectively). All samples had a two-phase state (rhombohedral R and monoclinic B19′ martensitic phases) at 295 K. The full-profile analysis of X-ray reflections of the B2 phase obtained at 393 K shows that the dislocation density increases from 1014 m−2 to 1015 m−2 after pressing with e = 1.84 and reaches 2·1015 m−2 when e increases to 9.55. It has been established by positron annihilation lifetime spectroscopy that dislocations are the main type of defects in initial samples and the only type of defects in samples after abc pressing. The lifetime of positrons trapped by dislocations is 166 ps, and the intensity of this component increases from 83% in the initial samples to 99.4% after pressing with e = 9.55. The initial samples contain a component with a positron lifetime of 192 ps (intensity 16.4%), which corresponds to the presence of monovacancies in the nickel sublattice of the B2 phase (concentration ≈10−5). This component is absent in the positron lifetime spectra in the samples after pressing. The results of the analysis of the Doppler broadening spectroscopy correlate with the data obtained by the positron annihilation lifetime spectroscopy.
Language:	English
Published:	2022
Subjects:	электронный ресурс труды учёных ТПУ titanium nickelide abc pressing dislocation density vacancies positron annihilation spectroscopy никелид титана позитронная спектроскопия
Online Access:	http://earchive.tpu.ru/handle/11683/73242 https://doi.org/10.3390/ma15124298
Format:	Electronic Book Chapter
KOHA link:	https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=668166