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Comparison of Hot Deformation Behavior Characteristics Between As-Cast and Extruded Al-Zn-Mg-Cu (7075) Aluminum Alloys with a Similar Grain Size

The hot compressive behavior and processing maps of as-cast and extruded 7075 aluminum alloys with a similar grain size (320–350 μm) were studied and compared, which allows us to directly observe the effect of segregated phases in the as-cast microstructure on the deformation behavior and hot workab...

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Autores principales: Jeong, H.T., Kim, W.J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926894/
https://www.ncbi.nlm.nih.gov/pubmed/31756980
http://dx.doi.org/10.3390/ma12233807
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author Jeong, H.T.
Kim, W.J.
author_facet Jeong, H.T.
Kim, W.J.
author_sort Jeong, H.T.
collection PubMed
description The hot compressive behavior and processing maps of as-cast and extruded 7075 aluminum alloys with a similar grain size (320–350 μm) were studied and compared, which allows us to directly observe the effect of segregated phases in the as-cast microstructure on the deformation behavior and hot workability of 7075 alloys. In the as-cast alloy, the compound phases segregated along the interdendritic interfaces within the interiors of original grains provided the additional sites for continuous dynamic recrystallization via the particle stimulation nucleation mechanism. As a result, the as-cast alloy exhibited higher fractions of recrystallized grains and smaller grain sizes than the extruded alloy after compression. The stress exponent values of the as-cast alloy were smaller than those of the extruded alloy. In the processing maps, the domain associated with high power dissipation efficiencies (≥35%) occurred in a wider temperature range in the as-cast alloy compared to the extruded alloy. The segregated phases that remained undissolved in the as-cast alloy after compressive deformation could be effectively eliminated during the solid solution treatment (753 K for 2 h) for T6 aging applied after hot compression. The current results suggest the possibility and advantage of omitting the extrusion step when preparing 7xxx aluminum forging or extrusion feedstocks for hot working. The proposed method can be applied to other precipitation hardenable aluminum alloys.
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spelling pubmed-69268942019-12-23 Comparison of Hot Deformation Behavior Characteristics Between As-Cast and Extruded Al-Zn-Mg-Cu (7075) Aluminum Alloys with a Similar Grain Size Jeong, H.T. Kim, W.J. Materials (Basel) Article The hot compressive behavior and processing maps of as-cast and extruded 7075 aluminum alloys with a similar grain size (320–350 μm) were studied and compared, which allows us to directly observe the effect of segregated phases in the as-cast microstructure on the deformation behavior and hot workability of 7075 alloys. In the as-cast alloy, the compound phases segregated along the interdendritic interfaces within the interiors of original grains provided the additional sites for continuous dynamic recrystallization via the particle stimulation nucleation mechanism. As a result, the as-cast alloy exhibited higher fractions of recrystallized grains and smaller grain sizes than the extruded alloy after compression. The stress exponent values of the as-cast alloy were smaller than those of the extruded alloy. In the processing maps, the domain associated with high power dissipation efficiencies (≥35%) occurred in a wider temperature range in the as-cast alloy compared to the extruded alloy. The segregated phases that remained undissolved in the as-cast alloy after compressive deformation could be effectively eliminated during the solid solution treatment (753 K for 2 h) for T6 aging applied after hot compression. The current results suggest the possibility and advantage of omitting the extrusion step when preparing 7xxx aluminum forging or extrusion feedstocks for hot working. The proposed method can be applied to other precipitation hardenable aluminum alloys. MDPI 2019-11-20 /pmc/articles/PMC6926894/ /pubmed/31756980 http://dx.doi.org/10.3390/ma12233807 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
Jeong, H.T.
Kim, W.J.
Comparison of Hot Deformation Behavior Characteristics Between As-Cast and Extruded Al-Zn-Mg-Cu (7075) Aluminum Alloys with a Similar Grain Size
title Comparison of Hot Deformation Behavior Characteristics Between As-Cast and Extruded Al-Zn-Mg-Cu (7075) Aluminum Alloys with a Similar Grain Size
title_full Comparison of Hot Deformation Behavior Characteristics Between As-Cast and Extruded Al-Zn-Mg-Cu (7075) Aluminum Alloys with a Similar Grain Size
title_fullStr Comparison of Hot Deformation Behavior Characteristics Between As-Cast and Extruded Al-Zn-Mg-Cu (7075) Aluminum Alloys with a Similar Grain Size
title_full_unstemmed Comparison of Hot Deformation Behavior Characteristics Between As-Cast and Extruded Al-Zn-Mg-Cu (7075) Aluminum Alloys with a Similar Grain Size
title_short Comparison of Hot Deformation Behavior Characteristics Between As-Cast and Extruded Al-Zn-Mg-Cu (7075) Aluminum Alloys with a Similar Grain Size
title_sort comparison of hot deformation behavior characteristics between as-cast and extruded al-zn-mg-cu (7075) aluminum alloys with a similar grain size
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6926894/
https://www.ncbi.nlm.nih.gov/pubmed/31756980
http://dx.doi.org/10.3390/ma12233807
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