HAADF-STEM study of β-type precipitates in an over-aged Al-Mg-Si-Ag alloy

C. D. Marioara; J. Nakamura; K. Matsuda; S. J. Andersen; R. Holmestad; T. Sato; T. Kawabata; S. Ikeno

doi:10.1080/14786435.2011.642319

HAADF-STEM study of β-type precipitates in an over-aged Al-Mg-Si-Ag alloy

C. D. Marioara^*, J. Nakamura, K. Matsuda, S. J. Andersen, R. Holmestad, T. Sato, T. Kawabata, S. Ikeno

^*Corresponding author for this work

Materials Design and Engineering

Research output: Contribution to journal › Article › peer-review

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Abstract

Coarse, rod-shaped precipitates growing along 100Al directions in an Al-1.0wt% Mg ₂Si alloy with 0.5wt% Ag additions were investigated by high-resolution high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). All investigated precipitates had complex structures, being composed of domains separated by anti-phase resembling boundaries. The domains consist of a modified hexagonal β-type structure that contains a considerable amount of Ag. Based on HAADF-STEM images, an average atomic model with space group P-62m (189) and composition Al3Mg3Si2Ag is proposed, having Al incorporation and Ag replacing certain Si atomic columns. Co-existence with the Ag-free β-Mg ₉Si ₅ phase has been observed for some precipitates. The boundaries may be described as full or half units of the orthorhombic U2-AlMgSi precipitate phase. The HAADF-STEM images indicate partial replacements of Al atoms by Ag, in both the β-type domains and the U2-type boundaries. Ag enrichment of the Al matrix near the precipitate/Al interface was observed for all the investigated precipitates

Original language	English
Pages (from-to)	1149-1158
Number of pages	10
Journal	Philosophical Magazine
Volume	92
Issue number	9
DOIs	https://doi.org/10.1080/14786435.2011.642319
State	Published - 2012/03/21

Keywords

aluminium-magnesium-silicon alloy
high resolution
high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM)
precipitate
silver addition

ASJC Scopus subject areas

Condensed Matter Physics

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10.1080/14786435.2011.642319

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@article{8888524aaa3f4a0b88df9c1f52837c12,

title = "HAADF-STEM study of β-type precipitates in an over-aged Al-Mg-Si-Ag alloy",

abstract = "Coarse, rod-shaped precipitates growing along 100Al directions in an Al-1.0wt% Mg 2Si alloy with 0.5wt% Ag additions were investigated by high-resolution high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). All investigated precipitates had complex structures, being composed of domains separated by anti-phase resembling boundaries. The domains consist of a modified hexagonal β-type structure that contains a considerable amount of Ag. Based on HAADF-STEM images, an average atomic model with space group P-62m (189) and composition Al3Mg3Si2Ag is proposed, having Al incorporation and Ag replacing certain Si atomic columns. Co-existence with the Ag-free β-Mg 9Si 5 phase has been observed for some precipitates. The boundaries may be described as full or half units of the orthorhombic U2-AlMgSi precipitate phase. The HAADF-STEM images indicate partial replacements of Al atoms by Ag, in both the β-type domains and the U2-type boundaries. Ag enrichment of the Al matrix near the precipitate/Al interface was observed for all the investigated precipitates",

keywords = "aluminium-magnesium-silicon alloy, high resolution, high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), precipitate, silver addition",

author = "Marioara, {C. D.} and J. Nakamura and K. Matsuda and Andersen, {S. J.} and R. Holmestad and T. Sato and T. Kawabata and S. Ikeno",

note = "Funding Information: This work was financially supported by the Norwegian Research Council via two projects: the {\textquoteleft}KMB-BILAT Norwegian Japanese Al–Mg–Si alloy precipitation project{\textquoteright}, also financed by Hydro Aluminium AS, and {\textquoteleft}BIA-Kimdanningskontroll (Precipitation Control){\textquoteright}, also financed by Hydro Aluminium AS and Steertec Raufoss AS. Research by HRTEM was supported by Japan Science Technology Agency (project ID: 07-B01). The authors also thank Dr E. Okunishi, JEOL, Japan, for his support in obtaining the HAADF-STEM images.",

year = "2012",

month = mar,

day = "21",

doi = "10.1080/14786435.2011.642319",

language = "英語",

volume = "92",

pages = "1149--1158",

journal = "Philosophical Magazine",

issn = "1478-6435",

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TY - JOUR

T1 - HAADF-STEM study of β-type precipitates in an over-aged Al-Mg-Si-Ag alloy

AU - Marioara, C. D.

AU - Nakamura, J.

AU - Matsuda, K.

AU - Andersen, S. J.

AU - Holmestad, R.

AU - Sato, T.

AU - Kawabata, T.

AU - Ikeno, S.

N1 - Funding Information: This work was financially supported by the Norwegian Research Council via two projects: the ‘KMB-BILAT Norwegian Japanese Al–Mg–Si alloy precipitation project’, also financed by Hydro Aluminium AS, and ‘BIA-Kimdanningskontroll (Precipitation Control)’, also financed by Hydro Aluminium AS and Steertec Raufoss AS. Research by HRTEM was supported by Japan Science Technology Agency (project ID: 07-B01). The authors also thank Dr E. Okunishi, JEOL, Japan, for his support in obtaining the HAADF-STEM images.

PY - 2012/3/21

Y1 - 2012/3/21

N2 - Coarse, rod-shaped precipitates growing along 100Al directions in an Al-1.0wt% Mg 2Si alloy with 0.5wt% Ag additions were investigated by high-resolution high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). All investigated precipitates had complex structures, being composed of domains separated by anti-phase resembling boundaries. The domains consist of a modified hexagonal β-type structure that contains a considerable amount of Ag. Based on HAADF-STEM images, an average atomic model with space group P-62m (189) and composition Al3Mg3Si2Ag is proposed, having Al incorporation and Ag replacing certain Si atomic columns. Co-existence with the Ag-free β-Mg 9Si 5 phase has been observed for some precipitates. The boundaries may be described as full or half units of the orthorhombic U2-AlMgSi precipitate phase. The HAADF-STEM images indicate partial replacements of Al atoms by Ag, in both the β-type domains and the U2-type boundaries. Ag enrichment of the Al matrix near the precipitate/Al interface was observed for all the investigated precipitates

AB - Coarse, rod-shaped precipitates growing along 100Al directions in an Al-1.0wt% Mg 2Si alloy with 0.5wt% Ag additions were investigated by high-resolution high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). All investigated precipitates had complex structures, being composed of domains separated by anti-phase resembling boundaries. The domains consist of a modified hexagonal β-type structure that contains a considerable amount of Ag. Based on HAADF-STEM images, an average atomic model with space group P-62m (189) and composition Al3Mg3Si2Ag is proposed, having Al incorporation and Ag replacing certain Si atomic columns. Co-existence with the Ag-free β-Mg 9Si 5 phase has been observed for some precipitates. The boundaries may be described as full or half units of the orthorhombic U2-AlMgSi precipitate phase. The HAADF-STEM images indicate partial replacements of Al atoms by Ag, in both the β-type domains and the U2-type boundaries. Ag enrichment of the Al matrix near the precipitate/Al interface was observed for all the investigated precipitates

KW - aluminium-magnesium-silicon alloy

KW - high resolution

KW - high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM)

KW - precipitate

KW - silver addition

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U2 - 10.1080/14786435.2011.642319

DO - 10.1080/14786435.2011.642319

M3 - 学術論文

AN - SCOPUS:84863283540

SN - 1478-6435

VL - 92

SP - 1149

EP - 1158

JO - Philosophical Magazine

JF - Philosophical Magazine

IS - 9

ER -

HAADF-STEM study of β-type precipitates in an over-aged Al-Mg-Si-Ag alloy

Abstract

Keywords

ASJC Scopus subject areas

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