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Plastic flow at the theoretical yield stress in ceramic films

Published version
Peer-reviewed

Repository DOI


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Authors

Liu, S 
Wheeler, JM 
Michler, J 
Zeng, XT 
Clegg, WJ 

Abstract

Using fine-grained ceramic films based on chromium nitride, and suppressing fracture by using microcompression, it is shown that plastic flow at the theoretical yield stress can be obtained in brittle materials, with shear yield stresses of ~ G/24 at room temperature, which extrapolate to ~ G/19 at 0 K. Surprisingly, it is also found that the rate of deformation, and hence the hardness and the yield stress, are determined not by the soft, glassy grain boundary phase in the fine-grained materials, but by the harder crystal phase.

Description

Keywords

Hard coating, Dislocation nucleation, Micropillar compression, Deformation kinetics

Journal Title

Scripta Materialia

Conference Name

Journal ISSN

1359-6462

Volume Title

117

Publisher

Elsevier
Sponsorship
Engineering and Physical Sciences Research Council (EP/M005607/1)
This research was funded by A*STAR, Singapore and the Engineering and Physical Sciences Research Council (EPSRC) and Rolls-Royce Strategic Partnership (EP/H500375/1).