Cargando…

Crystal Structure Defects in Titanium Nickelide after Abc Pressing at Lowered Temperature

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 Ti(49.8)Ni(50.2) (at %) alloy are presented. It is shown that all samples (reg...

Descripción completa

Detalles Bibliográficos
Autores principales: Lotkov, Aleksandr, Grishkov, Victor, Laptev, Roman, Mironov, Yuri, Zhapova, Dorzhima, Girsova, Natalia, Gusarenko, Angelina, Barmina, Elena, Kashina, Olga
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9227948/
https://www.ncbi.nlm.nih.gov/pubmed/35744353
http://dx.doi.org/10.3390/ma15124298
_version_ 1784734314589585408
author Lotkov, Aleksandr
Grishkov, Victor
Laptev, Roman
Mironov, Yuri
Zhapova, Dorzhima
Girsova, Natalia
Gusarenko, Angelina
Barmina, Elena
Kashina, Olga
author_facet Lotkov, Aleksandr
Grishkov, Victor
Laptev, Roman
Mironov, Yuri
Zhapova, Dorzhima
Girsova, Natalia
Gusarenko, Angelina
Barmina, Elena
Kashina, Olga
author_sort Lotkov, Aleksandr
collection PubMed
description 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 Ti(49.8)Ni(50.2) (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 10(14) m(−2) to 10(15) m(−2) after pressing with e = 1.84 and reaches 2·10(15) 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.
format Online
Article
Text
id pubmed-9227948
institution National Center for Biotechnology Information
language English
publishDate 2022
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-92279482022-06-25 Crystal Structure Defects in Titanium Nickelide after Abc Pressing at Lowered Temperature Lotkov, Aleksandr Grishkov, Victor Laptev, Roman Mironov, Yuri Zhapova, Dorzhima Girsova, Natalia Gusarenko, Angelina Barmina, Elena Kashina, Olga Materials (Basel) Article 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 Ti(49.8)Ni(50.2) (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 10(14) m(−2) to 10(15) m(−2) after pressing with e = 1.84 and reaches 2·10(15) 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. MDPI 2022-06-17 /pmc/articles/PMC9227948/ /pubmed/35744353 http://dx.doi.org/10.3390/ma15124298 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Lotkov, Aleksandr
Grishkov, Victor
Laptev, Roman
Mironov, Yuri
Zhapova, Dorzhima
Girsova, Natalia
Gusarenko, Angelina
Barmina, Elena
Kashina, Olga
Crystal Structure Defects in Titanium Nickelide after Abc Pressing at Lowered Temperature
title Crystal Structure Defects in Titanium Nickelide after Abc Pressing at Lowered Temperature
title_full Crystal Structure Defects in Titanium Nickelide after Abc Pressing at Lowered Temperature
title_fullStr Crystal Structure Defects in Titanium Nickelide after Abc Pressing at Lowered Temperature
title_full_unstemmed Crystal Structure Defects in Titanium Nickelide after Abc Pressing at Lowered Temperature
title_short Crystal Structure Defects in Titanium Nickelide after Abc Pressing at Lowered Temperature
title_sort crystal structure defects in titanium nickelide after abc pressing at lowered temperature
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9227948/
https://www.ncbi.nlm.nih.gov/pubmed/35744353
http://dx.doi.org/10.3390/ma15124298
work_keys_str_mv AT lotkovaleksandr crystalstructuredefectsintitaniumnickelideafterabcpressingatloweredtemperature
AT grishkovvictor crystalstructuredefectsintitaniumnickelideafterabcpressingatloweredtemperature
AT laptevroman crystalstructuredefectsintitaniumnickelideafterabcpressingatloweredtemperature
AT mironovyuri crystalstructuredefectsintitaniumnickelideafterabcpressingatloweredtemperature
AT zhapovadorzhima crystalstructuredefectsintitaniumnickelideafterabcpressingatloweredtemperature
AT girsovanatalia crystalstructuredefectsintitaniumnickelideafterabcpressingatloweredtemperature
AT gusarenkoangelina crystalstructuredefectsintitaniumnickelideafterabcpressingatloweredtemperature
AT barminaelena crystalstructuredefectsintitaniumnickelideafterabcpressingatloweredtemperature
AT kashinaolga crystalstructuredefectsintitaniumnickelideafterabcpressingatloweredtemperature