Multi-Scale Mechanical Property Characterisation of Quasi-Brittle Filter Graphite

Abstract:

In this paper PG25 filter graphite is characterised using mechanical tests conducted over a range of specimen length-scales from the centimetre (three-point bending and Brazilian disc compression) to the micrometre (micro-scale cantilever bending in a FEI Helios dualbeam work station). However, high resolution 3D tomography has revealed that apart from the known millimetre range of pores, the matrix contains a large population of micro-scale porosity. This leads to two discrete distributions of pore sizes in this material, so that a reduction in mechanical test specimen size results in sampling different proportions of the milli-and micro-scale pores. As a consequence, the measured mechanical properties such as elastic modulus, tensile strength and flexural strength change as a function of specimen size. This paper explores the potential benefits, difficulties and value of small-scale mechanical tests for this particular application.

• Periodical: Key Engineering Materials (Volume 627)
• Pages: 53-56
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.627.53
• Online since: September 2014
• Authors: Dong Liu*, Peter J. Heard, Peter E.J. Flewitt, David J. Smith
• Keywords: Micro-Cantilever Bending, Multi-Scale Tests, Porous Graphite, Quasi-Brittle

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DOI: 10.1179/1743284713y.0000000354