Evolution of gradient structured layer on AZ91D magnesium alloy and its corrosion behaviour
(2021) In Journal of Alloys and Compounds 882.- Abstract
This article investigates the microstructure evolution and corrosion response of surface mechanical attrition treated (SMAT) AZ91D magnesium alloy. In-depth transmission electron microscopy and combined isothermal calorimetry and pressure measurement technique, a novel and powerful tool for in situ monitoring of the magnesium corrosion process, are explored in the present study. A gradient structured layer of ~ 500 µm thickness with improved (~2.5 times) surface hardness is successfully obtained on the AZ91D alloy surface. SMAT introduces compressive residual stress in the treated layer. TEM results confirmed nanoscale grains of ~125 nm in topmost region and multiple deformation twin-modes, including 101¯2 〈101¯1〉 dense twins and 101¯1... (More)
This article investigates the microstructure evolution and corrosion response of surface mechanical attrition treated (SMAT) AZ91D magnesium alloy. In-depth transmission electron microscopy and combined isothermal calorimetry and pressure measurement technique, a novel and powerful tool for in situ monitoring of the magnesium corrosion process, are explored in the present study. A gradient structured layer of ~ 500 µm thickness with improved (~2.5 times) surface hardness is successfully obtained on the AZ91D alloy surface. SMAT introduces compressive residual stress in the treated layer. TEM results confirmed nanoscale grains of ~125 nm in topmost region and multiple deformation twin-modes, including 101¯2 〈101¯1〉 dense twins and 101¯1 – 101¯2 double twinning in SMATed layer. Twining of secondary twins is established in the TEM analysis. Moreover, a twin density gradient is evident within the treated layer, where it decreases with an increase in depth. After 24 h of immersion in 0.9% NaCl solution, the average corrosion rate of SMATed and non-SMATed specimens is ~11.0 and ~3.8 mm/year, respectively. The corrosion product on non-SMATed specimens has densely packed nano-flakes morphology; however, the SMATed surface shows two different morphologies: sparse nanowires and porous honeycomb-like structure. The SMATed specimen's lower corrosion resistance is attributed to the combined effect of the high density of defects, rougher surface, and smaller volume fraction of β phase at the surface.
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- author
- Singh, Digvijay ; Basha, Dudekula A. ; Wadsö, Lars LU ; Orlov, Dmytro LU ; Matsushita, Yoshitaka ; Singh, Alok and Hosmani, Santosh S.
- organization
- publishing date
- 2021-11-15
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- AZ91D, Corrosion, Double twinning, Isothermal calorimetry, SMAT
- in
- Journal of Alloys and Compounds
- volume
- 882
- article number
- 160659
- publisher
- Elsevier
- external identifiers
-
- scopus:85107665046
- ISSN
- 0925-8388
- DOI
- 10.1016/j.jallcom.2021.160659
- project
- Topological control of microstructures for advanced material engineering
- Topologically designed magnesium alloys for biomedical applications
- language
- English
- LU publication?
- yes
- additional info
- Funding Information: The authors would like to acknowledge Science and Engineering Research Board (SERB) [Grant number EMR/2017/001196], Swedish Research Council [Vetenskapsr?det: Grant number 2016/03811], and Japan Society for the Promotion of Science (JSPS) KAKENHI [Grant number 19H 05819] to support this research. DS is thankful to National Institute for Materials Science (NIMS) Japan for providing a NIMS internship program fellowship. The authors acknowledge NIMS TEM station for supporting TEM studies. The authors would like to thank Mr. Ilyes Tayeb-Bey (Institut National des Sciences Applique?es de Lyon, France) for assistance in the corrosion testing. Funding Information: The authors would like to acknowledge Science and Engineering Research Board ( SERB ) [Grant number EMR/2017/001196 ], Swedish Research Council [Vetenskapsrådet: Grant number 2016/03811 ], and Japan Society for the Promotion of Science ( JSPS ) KAKENHI [Grant number 19H 05819 ] to support this research. DS is thankful to National Institute for Materials Science ( NIMS ) Japan for providing a NIMS internship program fellowship. The authors acknowledge NIMS TEM station for supporting TEM studies. The authors would like to thank Mr. Ilyes Tayeb-Bey (Institut National des Sciences Appliquées de Lyon, France) for assistance in the corrosion testing. Publisher Copyright: © 2021 Elsevier B.V. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.
- id
- 94a8750b-eb7a-4008-8943-e02c9a3f7c45
- date added to LUP
- 2021-06-27 07:41:45
- date last changed
- 2023-10-10 21:28:51
@article{94a8750b-eb7a-4008-8943-e02c9a3f7c45, abstract = {{<p>This article investigates the microstructure evolution and corrosion response of surface mechanical attrition treated (SMAT) AZ91D magnesium alloy. In-depth transmission electron microscopy and combined isothermal calorimetry and pressure measurement technique, a novel and powerful tool for in situ monitoring of the magnesium corrosion process, are explored in the present study. A gradient structured layer of ~ 500 µm thickness with improved (~2.5 times) surface hardness is successfully obtained on the AZ91D alloy surface. SMAT introduces compressive residual stress in the treated layer. TEM results confirmed nanoscale grains of ~125 nm in topmost region and multiple deformation twin-modes, including 101¯2 〈101¯1〉 dense twins and 101¯1 – 101¯2 double twinning in SMATed layer. Twining of secondary twins is established in the TEM analysis. Moreover, a twin density gradient is evident within the treated layer, where it decreases with an increase in depth. After 24 h of immersion in 0.9% NaCl solution, the average corrosion rate of SMATed and non-SMATed specimens is ~11.0 and ~3.8 mm/year, respectively. The corrosion product on non-SMATed specimens has densely packed nano-flakes morphology; however, the SMATed surface shows two different morphologies: sparse nanowires and porous honeycomb-like structure. The SMATed specimen's lower corrosion resistance is attributed to the combined effect of the high density of defects, rougher surface, and smaller volume fraction of β phase at the surface.</p>}}, author = {{Singh, Digvijay and Basha, Dudekula A. and Wadsö, Lars and Orlov, Dmytro and Matsushita, Yoshitaka and Singh, Alok and Hosmani, Santosh S.}}, issn = {{0925-8388}}, keywords = {{AZ91D; Corrosion; Double twinning; Isothermal calorimetry; SMAT}}, language = {{eng}}, month = {{11}}, publisher = {{Elsevier}}, series = {{Journal of Alloys and Compounds}}, title = {{Evolution of gradient structured layer on AZ91D magnesium alloy and its corrosion behaviour}}, url = {{http://dx.doi.org/10.1016/j.jallcom.2021.160659}}, doi = {{10.1016/j.jallcom.2021.160659}}, volume = {{882}}, year = {{2021}}, }