Precipitation in a Ag-Containing Mg-Y-Zn Alloy

Y.M. Zhu, K. Oh-ishi, N.C. Wilson, K. Hono, A. J. Morton, J.F. Nie

Research output: Contribution to journalArticleResearchpeer-review

Abstract

The precipitation in a Mg-6Y-2Ag-1Zn-0.6Zr (wt pct) alloy during isothermal aging at and above 473 K (200 °C) has been examined systematically using conventional transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, and three-dimensional atom probe. The precipitation involves the formation of G.P. zones, metastable γ″ and γ′ phases, and equilibrium 14H and δ phases. The G.P. zones are a single atomic layer on (0001)α. The γ″ is the key strengthening phase and it has an ordered hexagonal structure (P6/mmm, a = 0.556 nm, c = 0.424 nm). The γ″ forms as (0001)α plates with a thickness of a single unit cell height and tends to develop into stacks with irregular spacing when the alloy is exposed to longer aging time at 473 K (200 °C). The γ″ is gradually replaced by γ′ and 14H during prolonged aging at 473 K (200 °C) and/or temperatures above 473 K (200 °C). The equilibrium δ phase is also found in grain boundaries. The results are compared with findings in other but similar alloy systems, and approaches for enhancing γ″ nucleation rate and hence further improvement in alloy age-hardening response are discussed. The effects of Ag on precipitation are also discussed.

Original languageEnglish
Pages (from-to)927-940
Number of pages14
JournalMetallurgical and Materials Transactions A - Physical Metallurgy and Materials Science
Volume47A
Issue number2
DOIs
Publication statusPublished - 1 Feb 2016

Cite this

Zhu, Y.M. ; Oh-ishi, K. ; Wilson, N.C. ; Hono, K. ; Morton, A. J. ; Nie, J.F. / Precipitation in a Ag-Containing Mg-Y-Zn Alloy. In: Metallurgical and Materials Transactions A - Physical Metallurgy and Materials Science. 2016 ; Vol. 47A, No. 2. pp. 927-940.
@article{555a0fc2c093430e9c9decb4e750a2a2,
title = "Precipitation in a Ag-Containing Mg-Y-Zn Alloy",
abstract = "The precipitation in a Mg-6Y-2Ag-1Zn-0.6Zr (wt pct) alloy during isothermal aging at and above 473 K (200 °C) has been examined systematically using conventional transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, and three-dimensional atom probe. The precipitation involves the formation of G.P. zones, metastable γ″ and γ′ phases, and equilibrium 14H and δ phases. The G.P. zones are a single atomic layer on (0001)α. The γ″ is the key strengthening phase and it has an ordered hexagonal structure (P6/mmm, a = 0.556 nm, c = 0.424 nm). The γ″ forms as (0001)α plates with a thickness of a single unit cell height and tends to develop into stacks with irregular spacing when the alloy is exposed to longer aging time at 473 K (200 °C). The γ″ is gradually replaced by γ′ and 14H during prolonged aging at 473 K (200 °C) and/or temperatures above 473 K (200 °C). The equilibrium δ phase is also found in grain boundaries. The results are compared with findings in other but similar alloy systems, and approaches for enhancing γ″ nucleation rate and hence further improvement in alloy age-hardening response are discussed. The effects of Ag on precipitation are also discussed.",
author = "Y.M. Zhu and K. Oh-ishi and N.C. Wilson and K. Hono and Morton, {A. J.} and J.F. Nie",
year = "2016",
month = "2",
day = "1",
doi = "10.1007/s11661-015-3251-3",
language = "English",
volume = "47A",
pages = "927--940",
journal = "Metallurgical and Materials Transactions A - Physical Metallurgy and Materials Science",
issn = "1073-5623",
publisher = "Springer",
number = "2",

}

Precipitation in a Ag-Containing Mg-Y-Zn Alloy. / Zhu, Y.M.; Oh-ishi, K.; Wilson, N.C.; Hono, K.; Morton, A. J.; Nie, J.F.

In: Metallurgical and Materials Transactions A - Physical Metallurgy and Materials Science, Vol. 47A, No. 2, 01.02.2016, p. 927-940.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Precipitation in a Ag-Containing Mg-Y-Zn Alloy

AU - Zhu, Y.M.

AU - Oh-ishi, K.

AU - Wilson, N.C.

AU - Hono, K.

AU - Morton, A. J.

AU - Nie, J.F.

PY - 2016/2/1

Y1 - 2016/2/1

N2 - The precipitation in a Mg-6Y-2Ag-1Zn-0.6Zr (wt pct) alloy during isothermal aging at and above 473 K (200 °C) has been examined systematically using conventional transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, and three-dimensional atom probe. The precipitation involves the formation of G.P. zones, metastable γ″ and γ′ phases, and equilibrium 14H and δ phases. The G.P. zones are a single atomic layer on (0001)α. The γ″ is the key strengthening phase and it has an ordered hexagonal structure (P6/mmm, a = 0.556 nm, c = 0.424 nm). The γ″ forms as (0001)α plates with a thickness of a single unit cell height and tends to develop into stacks with irregular spacing when the alloy is exposed to longer aging time at 473 K (200 °C). The γ″ is gradually replaced by γ′ and 14H during prolonged aging at 473 K (200 °C) and/or temperatures above 473 K (200 °C). The equilibrium δ phase is also found in grain boundaries. The results are compared with findings in other but similar alloy systems, and approaches for enhancing γ″ nucleation rate and hence further improvement in alloy age-hardening response are discussed. The effects of Ag on precipitation are also discussed.

AB - The precipitation in a Mg-6Y-2Ag-1Zn-0.6Zr (wt pct) alloy during isothermal aging at and above 473 K (200 °C) has been examined systematically using conventional transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, and three-dimensional atom probe. The precipitation involves the formation of G.P. zones, metastable γ″ and γ′ phases, and equilibrium 14H and δ phases. The G.P. zones are a single atomic layer on (0001)α. The γ″ is the key strengthening phase and it has an ordered hexagonal structure (P6/mmm, a = 0.556 nm, c = 0.424 nm). The γ″ forms as (0001)α plates with a thickness of a single unit cell height and tends to develop into stacks with irregular spacing when the alloy is exposed to longer aging time at 473 K (200 °C). The γ″ is gradually replaced by γ′ and 14H during prolonged aging at 473 K (200 °C) and/or temperatures above 473 K (200 °C). The equilibrium δ phase is also found in grain boundaries. The results are compared with findings in other but similar alloy systems, and approaches for enhancing γ″ nucleation rate and hence further improvement in alloy age-hardening response are discussed. The effects of Ag on precipitation are also discussed.

UR - http://www.scopus.com/inward/record.url?scp=84954361990&partnerID=8YFLogxK

U2 - 10.1007/s11661-015-3251-3

DO - 10.1007/s11661-015-3251-3

M3 - Article

VL - 47A

SP - 927

EP - 940

JO - Metallurgical and Materials Transactions A - Physical Metallurgy and Materials Science

JF - Metallurgical and Materials Transactions A - Physical Metallurgy and Materials Science

SN - 1073-5623

IS - 2

ER -