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Insights into Toughening Particulate Brittle Composites

Published online by Cambridge University Press:  14 March 2011

I.J. Merchant ,
H.W. Chandler ,
R.J. Henderson ,
T. Stebbings  and
D.E. Macphee
I.J. Merchant
Affiliation:
Departments of Engineering and Chemistry, University of Aberdeen, Old Aberdeen AB24 3UE
H.W. Chandler
Affiliation:
Departments of Engineering and Chemistry, University of Aberdeen, Old Aberdeen AB24 3UE
R.J. Henderson
Affiliation:
Departments of Engineering and Chemistry, University of Aberdeen, Old Aberdeen AB24 3UE
T. Stebbings
Affiliation:
Departments of Engineering and Chemistry, University of Aberdeen, Old Aberdeen AB24 3UE
D.E. Macphee
Affiliation:
Departments of Engineering and Chemistry, University of Aberdeen, Old Aberdeen AB24 3UE
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Abstract

A conventional approach to the toughening of brittle materials has been to incorporate fibrous inclusions. These toughen the composite by acting as crack bridges, with energy being dissipated by frictional losses during pull-out of the fibre or by matrix failure on the scale of fibre surface roughness. In all cases, toughening has been achieved only where propagating macrocracks have interacted with an appreciable number of reinforcing inclusions. This paper considers the probability that toughening via crack-bridging in these fibrous and especially particulate toughened materials has not been optimised and proposes the idea that the frequency of interaction between crack and inclusion is strongly increased by un-bonding the inclusion from the matrix. Results from studies on cement-mortars are presented in support of this and show significant improvements in toughness associated with samples in which inclusions are deliberately un-bonded from the matrix in advance of the crack arriving.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 702: Symposium U – Advanced Fibers, Plastics, Laminates and Composites , 2001 , U7.2.1
Copyright
Copyright © Materials Research Society 2002

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References

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