Experimental investigation of the viscoplastic behaviours and microstructure evolutions of AZ31B and Elektron 717 Mg-alloys
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Published version
Author(s)
Type
Journal Article
Abstract
An insight into the thermo-mechanical behaviours of AZ31B and Elektron 717 magnesium alloys under the hot stamping conditions was established. High-temperature tensile tests (i.e. 350–450 °C) at a strain rate of 0.1 to 5/s were conducted to examine the material viscoplastic behaviours. Additionally, microstructure characterizations were performed, using the electron backscatter diffraction (EBSD), on the deformed samples to capture the underlying deformation mechanisms. Dynamic recrystallization (DRX) and texture formation were observed during the deformation at high temperature in both alloys and are the primary factors that affect the viscoplastic behaviours. The yield stress of both alloys reduced with increasing temperatures and reducing strain rates. More importantly, the ductility of the samples increased with both the temperatures and the strain rates. The higher ductility at higher strain rates was primarily attributed to finer grains and the slightly weakened textures, enabling a more uniform deformation. A maximum ductility of ~2 was observed in AZ31B under 450 °C at 1/s while ~0.9 in Elektron 717 under the identical condition. The addition of rare earth elements in Elektron 717 may suppress the active DRX. The recrystallization type was identified as discontinuous DRX. The research findings deliver understandings on the viscoplastic behaviours and the deformation mechanisms of AZ31B and Elektron 717 under the hot stamping conditions and provide scientific guidance for feasibility study on applying hot stamping technique to Mg-alloy for forming complex geometry components.
Date Issued
2019-12-15
Date Acceptance
2019-08-24
ISSN
0264-1275
Publisher
Elsevier
Start Page
1
End Page
13
Journal / Book Title
Materials and Design
Volume
184
Copyright Statement
© 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Contents lists available atScienceDirectMaterials and Designjournal homepage:www.elsevier.com/locate/matdes
Kai ZhangJing-Hua ZhengZhutaoShaoCatalin PruncuMarkTurskiCarlos GueriniJun Jiang
Kai ZhangJing-Hua ZhengZhutaoShaoCatalin PruncuMarkTurskiCarlos GueriniJun Jiang
Sponsor
Engineering & Physical Science Research Council (E
Identifier
https://www.sciencedirect.com/science/article/pii/S0264127519305982?via%3Dihub
Grant Number
EP/R001715/1 / PO 2058517
Subjects
0912 Materials Engineering
0913 Mechanical Engineering
0910 Manufacturing Engineering
Materials
Publication Status
Published online
Date Publish Online
2019-08-26