Plastic flow at the theoretical yield stress in ceramic films
Published version
Peer-reviewed
Repository URI
Repository DOI
Change log
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
Publisher DOI
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).