Discussion of the dependence of the effect of size on the yield stress in hard materials studied by microcompression of MgO

Microcompression has attracted considerable interest in the study of size effects, mainly in soft metals. Little data is available in the literature on experiments on materials with a higher bulk flow stress, although it has been shown that the technique can be successfully employed to suppress crac...

Full description

Saved in:
Bibliographic Details
Published in:Philosophical magazine (Abingdon, England) England), 2011-03, Vol.91 (7-9), p.1150-1162
Main Authors: Korte, S., Clegg, W.J.
Format: Article
Language:English
Subjects:
Brittle materials
Confining
Flow stress
Fracture mechanics
Magnesium oxide
microcompression
size effect
Slip
Yield strength
Yield stress
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Microcompression has attracted considerable interest in the study of size effects, mainly in soft metals. Little data is available in the literature on experiments on materials with a higher bulk flow stress, although it has been shown that the technique can be successfully employed to suppress cracking due to the small specimen dimensions. Here, microcompressions on MgO were carried out to demonstrate the possibility of individually activating different slip systems. The yield stresses obtained in conjunction with transmission electron microscopy show that both the hard and soft slip system in MgO can be characterised individually. Microcompression is, therefore, a potential alternative to macroscopic testing of brittle materials under confining pressure or at high temperatures. To determine the influence of size on such measurements, results on the two slip systems in MgO and from the literature are compared. It is found that the bulk yield stress of a material might be used to estimate the effect of size on its yield stress at the microscale.
ISSN:1478-6435
1478-6443
DOI:10.1080/14786435.2010.505179