Severe Plastic Deformation of Fe-22Al-5Cr Alloy by Cross-Channel Extrusion with Back Pressure

A new concept of the cross-channel extrusion (CCE) process under back pressure (BP) was proposed and tested experimentally. The obtained by finite element method (FEM) results showed that a triaxial compression occurred in the central zone, whereas the material was deformed by shearing in the outer...

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Main Authors: Radosław Łyszkowski, Wojciech Polkowski, Tomasz Czujko
Format: Article
Language:English
Published: MDPI AG 2018-11-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/11/11/2214
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spelling doaj-cfe2bf1b5de24e0e8bb8b4d7f24cdc682020-11-24T20:43:31ZengMDPI AGMaterials1996-19442018-11-011111221410.3390/ma11112214ma11112214Severe Plastic Deformation of Fe-22Al-5Cr Alloy by Cross-Channel Extrusion with Back PressureRadosław Łyszkowski0Wojciech Polkowski1Tomasz Czujko2Faculty of Advanced Technology and Chemistry, Military University of Technology, 2 Urbanowicza, 00-908 Warsaw, PolandFoundry Research Institute, 73 Zakopiańska, 30-418 Cracow, PolandFaculty of Advanced Technology and Chemistry, Military University of Technology, 2 Urbanowicza, 00-908 Warsaw, PolandA new concept of the cross-channel extrusion (CCE) process under back pressure (BP) was proposed and tested experimentally. The obtained by finite element method (FEM) results showed that a triaxial compression occurred in the central zone, whereas the material was deformed by shearing in the outer zone. This led to the presence of a relatively uniformly deformed outer zone at 1 per pass and a strong deformation of the paraxial zone (3⁻5/pass). An increase in the BP did not substantially affect the accumulated strain but made it more uniform. The FEM results were verified using the physical modeling technique (PMT) by the extrusion of clay billet. The formation of the plane of the strongly flattened, and elongated grains were observed in the extrusion directions. With the increase in the number of passes, the shape of the resulting patterns expanded, indicating an increase in the deformation homogeneity. Finally, these investigations were verified experimentally for Fe-22Al-5Cr (at. %) alloy using of the purposely designed tooling. The effect of the CCE process is the fragmentation of the original material structure by dividing the primary grains. The complexity of the stress state leads to the rapid growth of microshear bands (MSB), grain defragmentation and the nucleation of new dynamically recrystallized grains about 200⁻400 nm size.https://www.mdpi.com/1996-1944/11/11/2214severe plastic deformation (SPD)cross-channel extrusion (CCE)back pressure (BP)numerical simulation (FEM)physical modeling technique (PMT)
collection DOAJ
language English
format Article
sources DOAJ
author Radosław Łyszkowski
Wojciech Polkowski
Tomasz Czujko
spellingShingle Radosław Łyszkowski
Wojciech Polkowski
Tomasz Czujko
Severe Plastic Deformation of Fe-22Al-5Cr Alloy by Cross-Channel Extrusion with Back Pressure
Materials
severe plastic deformation (SPD)
cross-channel extrusion (CCE)
back pressure (BP)
numerical simulation (FEM)
physical modeling technique (PMT)
author_facet Radosław Łyszkowski
Wojciech Polkowski
Tomasz Czujko
author_sort Radosław Łyszkowski
title Severe Plastic Deformation of Fe-22Al-5Cr Alloy by Cross-Channel Extrusion with Back Pressure
title_short Severe Plastic Deformation of Fe-22Al-5Cr Alloy by Cross-Channel Extrusion with Back Pressure
title_full Severe Plastic Deformation of Fe-22Al-5Cr Alloy by Cross-Channel Extrusion with Back Pressure
title_fullStr Severe Plastic Deformation of Fe-22Al-5Cr Alloy by Cross-Channel Extrusion with Back Pressure
title_full_unstemmed Severe Plastic Deformation of Fe-22Al-5Cr Alloy by Cross-Channel Extrusion with Back Pressure
title_sort severe plastic deformation of fe-22al-5cr alloy by cross-channel extrusion with back pressure
publisher MDPI AG
series Materials
issn 1996-1944
publishDate 2018-11-01
description A new concept of the cross-channel extrusion (CCE) process under back pressure (BP) was proposed and tested experimentally. The obtained by finite element method (FEM) results showed that a triaxial compression occurred in the central zone, whereas the material was deformed by shearing in the outer zone. This led to the presence of a relatively uniformly deformed outer zone at 1 per pass and a strong deformation of the paraxial zone (3⁻5/pass). An increase in the BP did not substantially affect the accumulated strain but made it more uniform. The FEM results were verified using the physical modeling technique (PMT) by the extrusion of clay billet. The formation of the plane of the strongly flattened, and elongated grains were observed in the extrusion directions. With the increase in the number of passes, the shape of the resulting patterns expanded, indicating an increase in the deformation homogeneity. Finally, these investigations were verified experimentally for Fe-22Al-5Cr (at. %) alloy using of the purposely designed tooling. The effect of the CCE process is the fragmentation of the original material structure by dividing the primary grains. The complexity of the stress state leads to the rapid growth of microshear bands (MSB), grain defragmentation and the nucleation of new dynamically recrystallized grains about 200⁻400 nm size.
topic severe plastic deformation (SPD)
cross-channel extrusion (CCE)
back pressure (BP)
numerical simulation (FEM)
physical modeling technique (PMT)
url https://www.mdpi.com/1996-1944/11/11/2214
work_keys_str_mv AT radosławłyszkowski severeplasticdeformationoffe22al5cralloybycrosschannelextrusionwithbackpressure
AT wojciechpolkowski severeplasticdeformationoffe22al5cralloybycrosschannelextrusionwithbackpressure
AT tomaszczujko severeplasticdeformationoffe22al5cralloybycrosschannelextrusionwithbackpressure
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