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The Influence of A Cross-Channel Extrusion Process on The Microstructure and Properties of Copper

A new cross-channel extrusion (CCE) method with the application of a back pressure (BP) is proposed and experimentally tested. The introduction of pressure blocks the free flow of material by using an additional set of pistons, which prevents the loss of consistency. The paper presents results of ex...

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Autores principales: Łyszkowski, Radosław, Łazińska, Magdalena, Zasada, Dariusz
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926915/
https://www.ncbi.nlm.nih.gov/pubmed/31810224
http://dx.doi.org/10.3390/ma12233995
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author Łyszkowski, Radosław
Łazińska, Magdalena
Zasada, Dariusz
author_facet Łyszkowski, Radosław
Łazińska, Magdalena
Zasada, Dariusz
author_sort Łyszkowski, Radosław
collection PubMed
description A new cross-channel extrusion (CCE) method with the application of a back pressure (BP) is proposed and experimentally tested. The introduction of pressure blocks the free flow of material by using an additional set of pistons, which prevents the loss of consistency. The paper presents results of experimental trials of CCE process. Between one and eight passes of CCE with and without a BP were applied to pure copper billets to refine their initial coarse-grained microstructure at room temperature. It was found that processing by CCE results in the formation of a lamellar structure along the extruded axis and the fine-grained structure in the remaining volume. The material exhibited dynamic recrystallization, which results in the formation of 0.5- to 2-μm grains after one pass and 2- to 8-μm grains after four CCE passes. The fine-grained material had YS of 390-415 MPa. An increase in the microhardness from 70 to 130 HV02 after one pass and then a decrease after four passes were observed. This might indicate that secondary recrystallization and selective grain growth occur, because an exothermic peak (158.5 °C, 53 ± 2.1 J/mol) was observed during DSC (differential scanning calorimetry) testing. The resistivity of the once deformed copper significantly decreases, while its further processing causes the resistivity to increase.
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spelling pubmed-69269152019-12-23 The Influence of A Cross-Channel Extrusion Process on The Microstructure and Properties of Copper Łyszkowski, Radosław Łazińska, Magdalena Zasada, Dariusz Materials (Basel) Article A new cross-channel extrusion (CCE) method with the application of a back pressure (BP) is proposed and experimentally tested. The introduction of pressure blocks the free flow of material by using an additional set of pistons, which prevents the loss of consistency. The paper presents results of experimental trials of CCE process. Between one and eight passes of CCE with and without a BP were applied to pure copper billets to refine their initial coarse-grained microstructure at room temperature. It was found that processing by CCE results in the formation of a lamellar structure along the extruded axis and the fine-grained structure in the remaining volume. The material exhibited dynamic recrystallization, which results in the formation of 0.5- to 2-μm grains after one pass and 2- to 8-μm grains after four CCE passes. The fine-grained material had YS of 390-415 MPa. An increase in the microhardness from 70 to 130 HV02 after one pass and then a decrease after four passes were observed. This might indicate that secondary recrystallization and selective grain growth occur, because an exothermic peak (158.5 °C, 53 ± 2.1 J/mol) was observed during DSC (differential scanning calorimetry) testing. The resistivity of the once deformed copper significantly decreases, while its further processing causes the resistivity to increase. MDPI 2019-12-02 /pmc/articles/PMC6926915/ /pubmed/31810224 http://dx.doi.org/10.3390/ma12233995 Text en © 2019 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
Łyszkowski, Radosław
Łazińska, Magdalena
Zasada, Dariusz
The Influence of A Cross-Channel Extrusion Process on The Microstructure and Properties of Copper
title The Influence of A Cross-Channel Extrusion Process on The Microstructure and Properties of Copper
title_full The Influence of A Cross-Channel Extrusion Process on The Microstructure and Properties of Copper
title_fullStr The Influence of A Cross-Channel Extrusion Process on The Microstructure and Properties of Copper
title_full_unstemmed The Influence of A Cross-Channel Extrusion Process on The Microstructure and Properties of Copper
title_short The Influence of A Cross-Channel Extrusion Process on The Microstructure and Properties of Copper
title_sort influence of a cross-channel extrusion process on the microstructure and properties of copper
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926915/
https://www.ncbi.nlm.nih.gov/pubmed/31810224
http://dx.doi.org/10.3390/ma12233995
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