Baruah, D and Vaishakh, KV and Sreedhar, SA and Gupta, SK and Suwas, S and Narasimhan, R (2023) Notch sensitivity of combined mode I–II fracture behaviour of a rolled magnesium alloy. In: Philosophical Magazine Letters, 103 (1).
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Abstract
Fatigue pre-cracked four-point bend specimens of a rolled AZ31 Mg alloy are loaded asymmetrically and their mixed-mode (I and II) fracture behaviour is contrasted with pre-notched samples. In-situ mapping of displacement and strain fields is performed through optical imaging coupled with digital image correlation analysis. The fracture surface morphology and the deformed microstructure are also studied. The fracture toughness Jc for both types of specimens is highest for mode I and drops steeply with increase in mode II component. Furthermore, at the same level of mode-mixity, Jc for the notched samples is between two to three times the value pertaining to pre-cracked specimens. This is primarily attributed to quasi-brittle failure, irrespective of mode-mixity, for the latter, whereas the former display a combination of ductile and brittle fracture surface features. At the crack-initiation stage, more profuse tensile twinning is perceived at the far-edge of the ligament in the notched specimens, which also contributes to the observed toughness enhancement. © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
| Item Type: | Journal Article |
|---|---|
| Publication: | Philosophical Magazine Letters |
| Publisher: | Taylor and Francis Ltd. |
| Additional Information: | The copyright of this article belongs to the Authors. |
| Keywords: | Brittle fracture; Cracks; Ductile fracture; Fracture mechanics; Fracture toughness; Image correlation; Morphology; Optical correlation; Surface morphology; AZ31 Mg alloys; Displacement field; Four-point bend specimen; Fracture behavior; Mixed mode; Mixed mode fracture; Mode mixity; Notch sensitivity; Strain fields; Tensile twinning; Magnesium alloys |
| Department/Centre: | Division of Mechanical Sciences > Mechanical Engineering Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) |
| Date Deposited: | 10 Mar 2023 05:32 |
| Last Modified: | 10 Mar 2023 05:32 |
| URI: | https://eprints.iisc.ac.in/id/eprint/80928 |
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