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Interpreting Impedance Response of Silicon Carbide Whisker/Alumina Composites Through Microstructural Simulation
Author(s) -
Mebane David S.,
Gerhardt Rosario A.
Publication year - 2006
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2005.00710.x
Subject(s) - whisker , materials science , silicon carbide , composite material , percolation (cognitive psychology) , conductivity , ceramic , percolation threshold , electrical resistivity and conductivity , dielectric spectroscopy , composite number , electrical impedance , volume fraction , monte carlo method , chemistry , engineering , statistics , mathematics , electrode , electrochemistry , neuroscience , electrical engineering , biology
A three‐dimensional, object‐defined Monte Carlo simulation is applied to alumina‐silicon carbide whisker ceramic matrix composites. The simulation takes whisker orientation and size distributions into account simultaneously, and calculates a connectivity factor that relates whisker conductivity to macroscopic conductivity. Simulation results are compared with electrical measurements taken on real samples via impedance spectroscopy. Results show that the effect of whisker clumping can be seen in the impedance response as a decrease in the overall measured conductivity. Results also show that interfacial resistance influences the overall resistivity strongly relative to connectivity at volume fractions far above the percolation threshold. The possible mechanisms for interfacial resistance in the composite and their effect on the impedance response are discussed.