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The Effect of Different Thermal Treatment on the Allotropic fcc↔hcp Transformation and Compression Behavior of Polycrystalline Cobalt

Pure polycrystalline cobalt is systematically thermally treated in order to assess the effect of the microstructure on the compression behavior. Isothermal annealing of the as-drawn material leads to recrystallization and grain growth dependent on the annealing temperature (600–1100 [Formula: see te...

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Autores principales: Knapek, Michal, Minárik, Peter, Dobroň, Patrik, Šmilauerová, Jana, Celis, Mayerling Martinez, Hug, Eric, Chmelík, František
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
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Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7766495/
https://www.ncbi.nlm.nih.gov/pubmed/33348844
http://dx.doi.org/10.3390/ma13245775
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author Knapek, Michal
Minárik, Peter
Dobroň, Patrik
Šmilauerová, Jana
Celis, Mayerling Martinez
Hug, Eric
Chmelík, František
author_facet Knapek, Michal
Minárik, Peter
Dobroň, Patrik
Šmilauerová, Jana
Celis, Mayerling Martinez
Hug, Eric
Chmelík, František
author_sort Knapek, Michal
collection PubMed
description Pure polycrystalline cobalt is systematically thermally treated in order to assess the effect of the microstructure on the compression behavior. Isothermal annealing of the as-drawn material leads to recrystallization and grain growth dependent on the annealing temperature (600–1100 [Formula: see text] C). Consequently, the yield strength decreases and the fracture strain increases as a function of rising grain size; the content of the residual fcc phase is ~6–11%. Subsequent thermal cycling around the transition temperature is applied to further modify the microstructure, especially in terms of the fcc phase content. With the increasing number of cycles, the grain size further increases and the fraction of the fcc phase significantly drops. At the same time, the values of both the yield strength and fracture strain somewhat decrease. An atypical decrease in the fracture strain as a function of grain size is explained in terms of decreasing fcc phase content; the stress-induced fcc→hcp transformation can accommodate a significant amount of plastic strain. Besides controlling basic material parameters (e.g., grain size and texture), adjusting the content of the fcc phase can thus provide an effective means of mechanical performance optimization with respect to particular applications.
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spelling pubmed-77664952020-12-28 The Effect of Different Thermal Treatment on the Allotropic fcc↔hcp Transformation and Compression Behavior of Polycrystalline Cobalt Knapek, Michal Minárik, Peter Dobroň, Patrik Šmilauerová, Jana Celis, Mayerling Martinez Hug, Eric Chmelík, František Materials (Basel) Article Pure polycrystalline cobalt is systematically thermally treated in order to assess the effect of the microstructure on the compression behavior. Isothermal annealing of the as-drawn material leads to recrystallization and grain growth dependent on the annealing temperature (600–1100 [Formula: see text] C). Consequently, the yield strength decreases and the fracture strain increases as a function of rising grain size; the content of the residual fcc phase is ~6–11%. Subsequent thermal cycling around the transition temperature is applied to further modify the microstructure, especially in terms of the fcc phase content. With the increasing number of cycles, the grain size further increases and the fraction of the fcc phase significantly drops. At the same time, the values of both the yield strength and fracture strain somewhat decrease. An atypical decrease in the fracture strain as a function of grain size is explained in terms of decreasing fcc phase content; the stress-induced fcc→hcp transformation can accommodate a significant amount of plastic strain. Besides controlling basic material parameters (e.g., grain size and texture), adjusting the content of the fcc phase can thus provide an effective means of mechanical performance optimization with respect to particular applications. MDPI 2020-12-17 /pmc/articles/PMC7766495/ /pubmed/33348844 http://dx.doi.org/10.3390/ma13245775 Text en © 2020 by the authors. 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 (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Knapek, Michal
Minárik, Peter
Dobroň, Patrik
Šmilauerová, Jana
Celis, Mayerling Martinez
Hug, Eric
Chmelík, František
The Effect of Different Thermal Treatment on the Allotropic fcc↔hcp Transformation and Compression Behavior of Polycrystalline Cobalt
title The Effect of Different Thermal Treatment on the Allotropic fcc↔hcp Transformation and Compression Behavior of Polycrystalline Cobalt
title_full The Effect of Different Thermal Treatment on the Allotropic fcc↔hcp Transformation and Compression Behavior of Polycrystalline Cobalt
title_fullStr The Effect of Different Thermal Treatment on the Allotropic fcc↔hcp Transformation and Compression Behavior of Polycrystalline Cobalt
title_full_unstemmed The Effect of Different Thermal Treatment on the Allotropic fcc↔hcp Transformation and Compression Behavior of Polycrystalline Cobalt
title_short The Effect of Different Thermal Treatment on the Allotropic fcc↔hcp Transformation and Compression Behavior of Polycrystalline Cobalt
title_sort effect of different thermal treatment on the allotropic fcc↔hcp transformation and compression behavior of polycrystalline cobalt
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7766495/
https://www.ncbi.nlm.nih.gov/pubmed/33348844
http://dx.doi.org/10.3390/ma13245775
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