Plastic deformation of Mg17Al12 at 25–250 °C – properties and dislocation mechanisms

Mg17Al12 is a well-known precipitation phase in magnesium alloys containing aluminium. Although its low-temperature deformation mechanisms remain insufficiently understood, Mg17Al12 is known to co-deform with the hexagonal magnesium matrix under high stress at low temperatures and to soften above 15...

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Main Authors: Martina Freund, Zhuocheng Xie, Markus Kolb, Pei-Ling Sun, Marcus Hans, Jeffrey M. Wheeler, Sandra Korte-Kerzel
Format: Article
Language:English
Published: Elsevier 2025-07-01
Series:Materials & Design
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Online Access:http://www.sciencedirect.com/science/article/pii/S0264127525005714
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author Martina Freund
Zhuocheng Xie
Markus Kolb
Pei-Ling Sun
Marcus Hans
Jeffrey M. Wheeler
Sandra Korte-Kerzel
author_facet Martina Freund
Zhuocheng Xie
Markus Kolb
Pei-Ling Sun
Marcus Hans
Jeffrey M. Wheeler
Sandra Korte-Kerzel
author_sort Martina Freund
collection DOAJ
description Mg17Al12 is a well-known precipitation phase in magnesium alloys containing aluminium. Although its low-temperature deformation mechanisms remain insufficiently understood, Mg17Al12 is known to co-deform with the hexagonal magnesium matrix under high stress at low temperatures and to soften above 150 °C, thereby losing its reinforcing capability in magnesium alloys. In this work, we employ nanoindentation and micropillar compression to explore not only the mechanical properties of Mg17Al12 but also its underlying dislocation motion mechanisms. A pronounced reduction in yield stress occurs at and above 150 °C, accompanied by the disappearance of serrated plastic flow shown at lower temperatures and a more homogeneous flow manifested by the absence of surface slip traces. First data from atom probe tomography suggests that the observed serrations may arise from Al segregation to dislocations. We find that Mg17Al12 deforms on {110} planes and identify 〈11¯1〉 type Burgers vectors by transmission electron microscopy. Through atomistic simulations, we substantiate these results are substantiated by investigation of the possible slip planes, paths, and energy barriers and contrast the findings on Mg17Al12 with the mechanisms observed in the isostructural α-Mn.
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publisher Elsevier
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series Materials & Design
spelling doaj-art-71e58bb88fdd4115bd23932c2fc7d6e72025-08-20T02:10:06ZengElsevierMaterials & Design0264-12752025-07-0125511415110.1016/j.matdes.2025.114151Plastic deformation of Mg17Al12 at 25–250 °C – properties and dislocation mechanismsMartina Freund0Zhuocheng Xie1Markus Kolb2Pei-Ling Sun3Marcus Hans4Jeffrey M. Wheeler5Sandra Korte-Kerzel6Institute of Physical Metallurgy and Materials Physics, RWTH Aachen University, Kopernikusstraße 14, 52074 Aachen, Germany; Corresponding author.Institute of Physical Metallurgy and Materials Physics, RWTH Aachen University, Kopernikusstraße 14, 52074 Aachen, GermanyFriedrich-Alexander-Universität Erlangen-Nürnberg, Materials Science & Engineering, Institute 1, Martensstraße 5, 91058 Erlangen, GermanyInstitute of Physical Metallurgy and Materials Physics, RWTH Aachen University, Kopernikusstraße 14, 52074 Aachen, GermanyMaterials Chemistry, RWTH Aachen University, Aachen D-52074, GermanyEmpa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstrasse 39, Thun CH-3602, SwitzerlandInstitute of Physical Metallurgy and Materials Physics, RWTH Aachen University, Kopernikusstraße 14, 52074 Aachen, GermanyMg17Al12 is a well-known precipitation phase in magnesium alloys containing aluminium. Although its low-temperature deformation mechanisms remain insufficiently understood, Mg17Al12 is known to co-deform with the hexagonal magnesium matrix under high stress at low temperatures and to soften above 150 °C, thereby losing its reinforcing capability in magnesium alloys. In this work, we employ nanoindentation and micropillar compression to explore not only the mechanical properties of Mg17Al12 but also its underlying dislocation motion mechanisms. A pronounced reduction in yield stress occurs at and above 150 °C, accompanied by the disappearance of serrated plastic flow shown at lower temperatures and a more homogeneous flow manifested by the absence of surface slip traces. First data from atom probe tomography suggests that the observed serrations may arise from Al segregation to dislocations. We find that Mg17Al12 deforms on {110} planes and identify 〈11¯1〉 type Burgers vectors by transmission electron microscopy. Through atomistic simulations, we substantiate these results are substantiated by investigation of the possible slip planes, paths, and energy barriers and contrast the findings on Mg17Al12 with the mechanisms observed in the isostructural α-Mn.http://www.sciencedirect.com/science/article/pii/S0264127525005714IntermetallicDislocationsMg17Al12MagnesiumNanoindentationMicrocompression
spellingShingle Martina Freund
Zhuocheng Xie
Markus Kolb
Pei-Ling Sun
Marcus Hans
Jeffrey M. Wheeler
Sandra Korte-Kerzel
Plastic deformation of Mg17Al12 at 25–250 °C – properties and dislocation mechanisms
Materials & Design
Intermetallic
Dislocations
Mg17Al12
Magnesium
Nanoindentation
Microcompression
title Plastic deformation of Mg17Al12 at 25–250 °C – properties and dislocation mechanisms
title_full Plastic deformation of Mg17Al12 at 25–250 °C – properties and dislocation mechanisms
title_fullStr Plastic deformation of Mg17Al12 at 25–250 °C – properties and dislocation mechanisms
title_full_unstemmed Plastic deformation of Mg17Al12 at 25–250 °C – properties and dislocation mechanisms
title_short Plastic deformation of Mg17Al12 at 25–250 °C – properties and dislocation mechanisms
title_sort plastic deformation of mg17al12 at 25 250 °c properties and dislocation mechanisms
topic Intermetallic
Dislocations
Mg17Al12
Magnesium
Nanoindentation
Microcompression
url http://www.sciencedirect.com/science/article/pii/S0264127525005714
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