Phase transformations in an ultralight BCC Mg alloy during anisothermal ageing

Xin，Tongzheng1; Tang，Song2; Ji，Fan1; Cui，Luqing3; He，Binbin4; Lin，Xin5; Tian，Xiaolin6; Hou，Hua6,7; Zhao，Yuhong6,8; Ferry，Michael1

2022-10-15

10.1016/j.actamat.2022.118248

ACTA MATERIALIA   Impact Factor & Quartile

1359-6454

1873-2453

Mg-Li-Al alloys with a body-centred cubic (BCC) structure can exhibit exceptional specific strengths in combination with excellent ductility and corrosion resistance. In general, the strength of these alloys is very sensitive to the processing temperature due to the occurrence of various phase transformations. Although different phases have been identified in these alloys, their corresponding transformation mechanisms and unique role played in controlling the mechanical properties have never been studied in depth. In this work, we identified the phase transformation sequence by in-situ synchrotron X-ray diffraction. Moreover, we investigated the evolution of precipitation and their morphology using transmission and scanning electron microscopy, together with simulations based on the phase field modelling and first-principles calculations. Phase transformation sequence of Al-rich zone → θ (D0MgAl) → AlLi was confirmed during anisothermal ageing. A braided structure resulting from spinodal decomposition was found to be the optimized microstructure for achieving the peak strength. Nanocrystalline α-Mg phase at the interface between θ and the matrix was identified as the main reason for softening in the alloy. The core-shell model for θ → AlLi transformation is observed and verified. Our findings deepen the understanding of BCC Mg-Li-Al alloys and pave a pathway to develop new generation of ultralight alloys with stronger strength and better stability.

Mg alloys Phase transformations

SCI ; EI

English

Others

Natural Science Foundation of Jiangsu Province[BK20200503];Australian Research Council[DP190103592];

Materials Science ; Metallurgy & Metallurgical Engineering

Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering

WOS:000861076600005

PERGAMON-ELSEVIER SCIENCE LTD

20223412591158

Binary alloys ; Calculations ; Corrosion resistance ; Corrosion resistant alloys ; Crystal structure ; Lithium alloys ; Magnesium alloys ; Morphology ; Nanocrystals ; Phase transitions ; Processing ; Scanning electron microscopy ; Spinodal decomposition ; Ternary alloys

Metallurgy and Metallography:531 ; Metals Corrosion:539.1 ; Aluminum Alloys:541.2 ; Magnesium and Alloys:542.2 ; Lithium and Alloys:542.4 ; Alkali Metals:549.1 ; Alkaline Earth Metals:549.2 ; Nanotechnology:761 ; Physical Chemistry:801.4 ; Manufacturing:913.4 ; Mathematics:921 ; Physical Properties of Gases, Liquids and Solids:931.2 ; Atomic and Molecular Physics:931.3 ; Crystalline Solids:933.1 ; Crystal Lattice:933.1.1 ; Materials Science:951

MATERIALS SCIENCE

2-s2.0-85135904283

Scopus

1.School of Materials Science and Engineering,The University of New South Wales,Sydney,2052,Australia
2.Herbert Gleiter Institute of Nanoscience,School of Materials Science and Engineering,Nanjing University of Science and Technology,210094,China
3.Division of Engineering Materials,Department of Management and Engineering,Linköping University,Linköping,SE-58183,Sweden
4.Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,518055,China
5.State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an,127 West Youyi Road,710072,China
6.College of Materials Science and Engineering,North University of China,Taiyuan,030051,China
7.Taiyuan University of Science and Technology,Taiyuan,030024,China
8.Institute for Advanced Materials and Technology,University of Science and Technology Beijing,100083,China

Xin，Tongzheng,Tang，Song,Ji，Fan,et al. Phase transformations in an ultralight BCC Mg alloy during anisothermal ageing[J]. ACTA MATERIALIA,2022,239.

Xin，Tongzheng.,Tang，Song.,Ji，Fan.,Cui，Luqing.,He，Binbin.,...&Ferry，Michael.(2022).Phase transformations in an ultralight BCC Mg alloy during anisothermal ageing.ACTA MATERIALIA,239.

Xin，Tongzheng,et al."Phase transformations in an ultralight BCC Mg alloy during anisothermal ageing".ACTA MATERIALIA 239(2022).