Fracture mechanism and toughness of a rolled magnesium alloy under dynamic loading
Abstract
Static and dynamic fracture experiments are performed using fatigue pre-cracked three-point bend specimens of a rolled AZ31 Mg alloy on a servo-hydraulic universal testing machine and a Hopkinson bar setup, respectively. The results are interpreted using in-situ optical imaging along with digital image correlation analysis. Microstructural analysis reveals that the fracture mechanism changes from twin-induced quasi-brittle cracking for static loading to micro-void growth and coalescence under dynamic loading accompanied by decrease in tensile twinning near the tip with loading rate. By contrast, the density of twins near the far-edge of the ligament and associated texture change enhance strongly with loading rate. The fracture toughness increases dramatically at high loading rates which is attributed to enhanced work of separation and dissipation in the background plastic zone.
Additional Information
© 2020 Acta Materialia Inc. Published by Elsevier Ltd. Received 8 June 2020, Revised 14 October 2020, Accepted 26 October 2020, Available online 2 November 2020. R. Narasimhan would like to gratefully acknowledge the Science and Engineering Research Board (Government of India) for financial support through the J.C.Bose Fellowship research grant. The authors would like to thank Professor G. Ravichandran for providing experimental facilities and Dr. Zev Lovinger for helping with the dynamic tests. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.Attached Files
Supplemental Material - 1-s2.0-S1359645420308570-mmc1.xml
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Additional details
- Eprint ID
- 106435
- DOI
- 10.1016/j.actamat.2020.10.059
- Resolver ID
- CaltechAUTHORS:20201104-144153856
- Science and Engineering Research Board (SERB)
- Created
-
2020-11-05Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- GALCIT