Determination of Fracture Toughness and Fracture Probability of LPS Aluminas by Hertzian Indentation


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The Hertzian indentation technique has been evaluated as a possible means of assessing the surface fracture behaviour of a set of qualitatively similar liquid phase sintered polycrystalline aluminas with systematically varied composition, and a range of grain sizes. The method provides a better correlation between microstructure characteristics and surface fracture behaviour than does Vickers indentation. The fracture toughness determined from Hertzian indentations was found to be a function of grain size, irrespective of the composition of the material. The cumulative probabilities of formation of ring cracks at specific loads during indentation with a spherical indenter were determined for each material from the set of 25 measurements, and the parameters of distribution of the probability of fracture were calculated. A statistical correlation between the failure probability distribution and the size distribution of alumina grains was detected.



Edited by:

J. Dusza, R. Danzer and R. Morrell




D. Galusek et al., "Determination of Fracture Toughness and Fracture Probability of LPS Aluminas by Hertzian Indentation", Key Engineering Materials, Vol. 290, pp. 308-311, 2005

Online since:

July 2005




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