Bhattacharya, Manjima and Dalui, Srikanta and Dey, Nitai and Bysakh, Sandip and Ghosh, Jiten and Mukhopadhyay, Anoop Kumar (2016) Low strain rate compressive failure mechanism of coarse grain alumina. Ceramics International, 42 (8). pp. 9875-9886. ISSN 0272-8842

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The present work reports the dynamic compressive strength (sigma(c)) of a dense (similar to 95%) coarse grain (similar to 20 mu m) alumina measured at 30 degrees C as a function of strain rates ((epsilon) over dot) ranging from 10(-5) to 5 x 10(-1) s(-1). The results showed a unique 40% enhancement of (sigma(c)) with the increase in ((epsilon) over dot). Extensive post mortem examination of fracture fragments obtained from the compressive failure tests by FESEM, TEM and HRTEM confirmed the formation of micro-cracks, shear bands, nanoscale cleavages and dislocations whose recurrence had increased with strain rate. Both shear induced microplasticity and nanoscale cleavages as well as dislocations had occurred concurrently yet independently during compressive fracture of coarse grain alumina even at very low strain rates. Based on these evidences a new compressive failure mechanism of alumina was proposed. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Item Type: Article
Subjects: Engineering Materials
Divisions: Non-Oxide Ceramics & Composites
Depositing User: Bidhan Chaudhuri
Date Deposited: 10 Nov 2016 07:32
Last Modified: 10 Nov 2016 07:32

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