Deformation characteristics and strengthening-toughening mechanisms of heterostructured 2024Al alloy with various heterogeneity levels

Heterostructured (HS) 2024Al alloys with various heterogeneity levels, consisting of soft domains (CGs) and hard domains (FGs, Al3Tip, and eutectic compounds), were fabricated via adjusting the mold temperature of powder thixoforming. The results reveal that increasing the mold temperature leads to...

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Main Authors: G.F. Liu, T.J. Chen
Format: Article
Language:English
Published: Elsevier 2024-03-01
Series:Journal of Materials Research and Technology
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2238785424001091
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author G.F. Liu
T.J. Chen
author_facet G.F. Liu
T.J. Chen
author_sort G.F. Liu
collection DOAJ
description Heterostructured (HS) 2024Al alloys with various heterogeneity levels, consisting of soft domains (CGs) and hard domains (FGs, Al3Tip, and eutectic compounds), were fabricated via adjusting the mold temperature of powder thixoforming. The results reveal that increasing the mold temperature leads to a decrease in microhardness discrepancy between soft and hard domains from 2.12 to 1.08 GPa, and in volume fraction from 0.08 to 0.02, indicating a decrease in heterogeneity level. The alloy thixoformed at 250 °C exhibits a moderate heterogeneity level (the discrepancies in microhardness of 1.23 GPa and volume fraction of 0.04), which endows this alloy with the prominent comprehensive mechanical properties (ultimate tensile strength: 455 MPa, yield strength: 291 MPa, and elongation: 8.65 %). Furthermore, the deformation process of HS alloys occurs in a progressive order, starting from CGs, to FGs, then followed by eutectic compounds, and finally Al3Tip, i.e., the soft domains begin to deform first and then hard domains. The excellent ductility originates from the high hetero-deformation induced (HDI) hardening caused by the largest ability of dislocations accumulation at the interfaces of soft/hard domains. Additionally, the densified microstructure, relatively homogenized stress concentration after thixoforming, and the dislocations emitted from the submicro-Al3Tip also contribute to the strain hardening, and thus enhancing the ductility. In view of the heterogeneous structure, this work proposes a complex calculation model to predict the strength of the HS 2024Al alloys. The findings offer valuable insights into achieving optimal strength-ductility combination in HS alloys by the design of heterogeneous structure and fabrication technology.
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spelling doaj.art-b07c683848e14fa0b296c950c55fa7352024-03-24T06:57:17ZengElsevierJournal of Materials Research and Technology2238-78542024-03-0129616633Deformation characteristics and strengthening-toughening mechanisms of heterostructured 2024Al alloy with various heterogeneity levelsG.F. Liu0T.J. Chen1State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou, 730050, ChinaCorresponding author.; State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou, 730050, ChinaHeterostructured (HS) 2024Al alloys with various heterogeneity levels, consisting of soft domains (CGs) and hard domains (FGs, Al3Tip, and eutectic compounds), were fabricated via adjusting the mold temperature of powder thixoforming. The results reveal that increasing the mold temperature leads to a decrease in microhardness discrepancy between soft and hard domains from 2.12 to 1.08 GPa, and in volume fraction from 0.08 to 0.02, indicating a decrease in heterogeneity level. The alloy thixoformed at 250 °C exhibits a moderate heterogeneity level (the discrepancies in microhardness of 1.23 GPa and volume fraction of 0.04), which endows this alloy with the prominent comprehensive mechanical properties (ultimate tensile strength: 455 MPa, yield strength: 291 MPa, and elongation: 8.65 %). Furthermore, the deformation process of HS alloys occurs in a progressive order, starting from CGs, to FGs, then followed by eutectic compounds, and finally Al3Tip, i.e., the soft domains begin to deform first and then hard domains. The excellent ductility originates from the high hetero-deformation induced (HDI) hardening caused by the largest ability of dislocations accumulation at the interfaces of soft/hard domains. Additionally, the densified microstructure, relatively homogenized stress concentration after thixoforming, and the dislocations emitted from the submicro-Al3Tip also contribute to the strain hardening, and thus enhancing the ductility. In view of the heterogeneous structure, this work proposes a complex calculation model to predict the strength of the HS 2024Al alloys. The findings offer valuable insights into achieving optimal strength-ductility combination in HS alloys by the design of heterogeneous structure and fabrication technology.http://www.sciencedirect.com/science/article/pii/S2238785424001091Al alloyHeterogeneity levelPowder thixoformingDeformation characteristicsStrengthening and toughening
spellingShingle G.F. Liu
T.J. Chen
Deformation characteristics and strengthening-toughening mechanisms of heterostructured 2024Al alloy with various heterogeneity levels
Journal of Materials Research and Technology
Al alloy
Heterogeneity level
Powder thixoforming
Deformation characteristics
Strengthening and toughening
title Deformation characteristics and strengthening-toughening mechanisms of heterostructured 2024Al alloy with various heterogeneity levels
title_full Deformation characteristics and strengthening-toughening mechanisms of heterostructured 2024Al alloy with various heterogeneity levels
title_fullStr Deformation characteristics and strengthening-toughening mechanisms of heterostructured 2024Al alloy with various heterogeneity levels
title_full_unstemmed Deformation characteristics and strengthening-toughening mechanisms of heterostructured 2024Al alloy with various heterogeneity levels
title_short Deformation characteristics and strengthening-toughening mechanisms of heterostructured 2024Al alloy with various heterogeneity levels
title_sort deformation characteristics and strengthening toughening mechanisms of heterostructured 2024al alloy with various heterogeneity levels
topic Al alloy
Heterogeneity level
Powder thixoforming
Deformation characteristics
Strengthening and toughening
url http://www.sciencedirect.com/science/article/pii/S2238785424001091
work_keys_str_mv AT gfliu deformationcharacteristicsandstrengtheningtougheningmechanismsofheterostructured2024alalloywithvariousheterogeneitylevels
AT tjchen deformationcharacteristicsandstrengtheningtougheningmechanismsofheterostructured2024alalloywithvariousheterogeneitylevels