Intermetallic and dispersoid structures in AA3104 aluminium alloy during two-step homogenisation

Abstract During homogenisation of the AA3104 cast ingot, a phase transformation of intermetallic particles from β-Al6(Fe,Mn) orthorhombic phase to harder α-Alx(Fe,Mn)3Si2 cubic phase occurs. The large constituent intermetallic particles, regardless of phase, assist in the recrystallisation nucleatio...

Full description

Bibliographic Details
Main Authors: S. L. George, L. Magidi-Chicuba
Format: Article
Language:English
Published: Nature Portfolio 2024-02-01
Series:Scientific Reports
Online Access:https://doi.org/10.1038/s41598-024-51890-2
_version_ 1797274746609467392
author S. L. George
L. Magidi-Chicuba
author_facet S. L. George
L. Magidi-Chicuba
author_sort S. L. George
collection DOAJ
description Abstract During homogenisation of the AA3104 cast ingot, a phase transformation of intermetallic particles from β-Al6(Fe,Mn) orthorhombic phase to harder α-Alx(Fe,Mn)3Si2 cubic phase occurs. The large constituent intermetallic particles, regardless of phase, assist in the recrystallisation nucleation process through particle stimulated nucleation (PSN). Ultimately, this helps to refine grain size. The sub-micron dispersoids act to impede grain boundary migration through a Zener drag mechanism. For this reason, the dispersoids that form during homogenisation are critical to the recrystallisation kinetics during subsequent rolling, with smaller dispersoids being better suited to instances where the minimisation of recrystallisation is required during hot rolling. This work simulates an industrial two-step homogenisation practice with variations in the peak temperature of the first step between 560 °C and 580 °C. The effect of this temperature variation on the intermetallic particle phase evolution is investigated. The aim is to identify the ideal intermetallic phase balance and the dispersoid structure that are best suited for the minimisation of recrystallisation during hot rolling through maximising Zener drag and maintaining galling resistance. The results indicate a trend where an increase in homogenisation temperature from 560 °C to 580 °C yields, firstly, an increase in the volume fraction of the α-phase particles to greater than 50% of the total volume fraction at both the edge and the centre of the ingot and, secondly, it yields an increased dispersoid size. Thus, a lower temperature homogenisation practice produces a near-ideal combination of intermetallic particle phase distribution, as well as dispersoid size, which is critical for Zener drag and the minimization of recrystallisation during the hot rolling processes.
first_indexed 2024-03-07T15:02:41Z
format Article
id doaj.art-c64ef8f158f243ea96a3e402f641f156
institution Directory Open Access Journal
issn 2045-2322
language English
last_indexed 2024-03-07T15:02:41Z
publishDate 2024-02-01
publisher Nature Portfolio
record_format Article
series Scientific Reports
spelling doaj.art-c64ef8f158f243ea96a3e402f641f1562024-03-05T19:04:57ZengNature PortfolioScientific Reports2045-23222024-02-0114111110.1038/s41598-024-51890-2Intermetallic and dispersoid structures in AA3104 aluminium alloy during two-step homogenisationS. L. George0L. Magidi-Chicuba1Centre for Materials Engineering, Department of Mechanical Engineering, University of Cape TownCentre for Materials Engineering, Department of Mechanical Engineering, University of Cape TownAbstract During homogenisation of the AA3104 cast ingot, a phase transformation of intermetallic particles from β-Al6(Fe,Mn) orthorhombic phase to harder α-Alx(Fe,Mn)3Si2 cubic phase occurs. The large constituent intermetallic particles, regardless of phase, assist in the recrystallisation nucleation process through particle stimulated nucleation (PSN). Ultimately, this helps to refine grain size. The sub-micron dispersoids act to impede grain boundary migration through a Zener drag mechanism. For this reason, the dispersoids that form during homogenisation are critical to the recrystallisation kinetics during subsequent rolling, with smaller dispersoids being better suited to instances where the minimisation of recrystallisation is required during hot rolling. This work simulates an industrial two-step homogenisation practice with variations in the peak temperature of the first step between 560 °C and 580 °C. The effect of this temperature variation on the intermetallic particle phase evolution is investigated. The aim is to identify the ideal intermetallic phase balance and the dispersoid structure that are best suited for the minimisation of recrystallisation during hot rolling through maximising Zener drag and maintaining galling resistance. The results indicate a trend where an increase in homogenisation temperature from 560 °C to 580 °C yields, firstly, an increase in the volume fraction of the α-phase particles to greater than 50% of the total volume fraction at both the edge and the centre of the ingot and, secondly, it yields an increased dispersoid size. Thus, a lower temperature homogenisation practice produces a near-ideal combination of intermetallic particle phase distribution, as well as dispersoid size, which is critical for Zener drag and the minimization of recrystallisation during the hot rolling processes.https://doi.org/10.1038/s41598-024-51890-2
spellingShingle S. L. George
L. Magidi-Chicuba
Intermetallic and dispersoid structures in AA3104 aluminium alloy during two-step homogenisation
Scientific Reports
title Intermetallic and dispersoid structures in AA3104 aluminium alloy during two-step homogenisation
title_full Intermetallic and dispersoid structures in AA3104 aluminium alloy during two-step homogenisation
title_fullStr Intermetallic and dispersoid structures in AA3104 aluminium alloy during two-step homogenisation
title_full_unstemmed Intermetallic and dispersoid structures in AA3104 aluminium alloy during two-step homogenisation
title_short Intermetallic and dispersoid structures in AA3104 aluminium alloy during two-step homogenisation
title_sort intermetallic and dispersoid structures in aa3104 aluminium alloy during two step homogenisation
url https://doi.org/10.1038/s41598-024-51890-2
work_keys_str_mv AT slgeorge intermetallicanddispersoidstructuresinaa3104aluminiumalloyduringtwostephomogenisation
AT lmagidichicuba intermetallicanddispersoidstructuresinaa3104aluminiumalloyduringtwostephomogenisation