title: The effect of wall thickness distribution on mechanical reliability and strength in unidirectional porous ceramics.
abstract: Macroporous ceramics exhibit an intrinsic strength variability caused by the random distribution of defects in their structure. However, the precise role of microstructural features, other than pore volume, on reliability is still unknown. Here, we analyze the applicability of the Weibull analysis to unidirectional macroporous yttria-stabilized-zirconia (YSZ) prepared by ice-templating. First, we performed crush tests on samples with controlled microstructural features with the loading direction parallel to the porosity. The compressive strength data were fitted using two different fitting techniques, ordinary least squares and Bayesian Markov Chain Monte Carlo, to evaluate whether Weibull statistics are an adequate descriptor of the strength distribution. The statistical descriptors indicated that the strength data are well described by the Weibull statistical approach, for both fitting methods used. Furthermore, we assess the effect of different microstructural features (volume, size, densification of the walls, and morphology) on Weibull modulus and strength. We found that the key microstructural parameter controlling reliability is wall thickness. In contrast, pore volume is the main parameter controlling the strength. The highest Weibull modulus ([Formula: see text]) and mean strength (198.2 MPa) were obtained for the samples with the smallest and narrowest wall thickness distribution (3.1 [Formula: see text]m) and lower pore volume (54.5%).
authors.affiliation: Laboratoire de Synthese et Fonctionnalisation des Ceramiques, UMR3080 CNRS/Saint-Gobain , F-84306 Cavaillon , France .
authors.forename: Jordi
authors.initials: J
authors.lastname: Seuba
authors.affiliation: Laboratoire de Synthese et Fonctionnalisation des Ceramiques, UMR3080 CNRS/Saint-Gobain , F-84306 Cavaillon , France .
authors.forename: Sylvain
authors.initials: S
authors.lastname: Deville
authors.affiliation: Institut Europeen des Membranes, Universite de Montpellier 2 , Place Eugene Bataillon , 34095 Montpellier Cedex 5 , France .
authors.forename: Christian
authors.initials: C
authors.lastname: Guizard
authors.affiliation: Laboratoire de Synthese et Fonctionnalisation des Ceramiques, UMR3080 CNRS/Saint-Gobain , F-84306 Cavaillon , France .
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Stevenson
keywords: 10 Engineering and structural materials\and 102Porous/Nanoporous/Nanostructured materials; 107 Glass and ceramicmaterials; 205Catalyst/Photocatalyst/Photosynthesis; 206 Conversion/transport/storage/recovery; 303 Mechanical/Physicalprocessing; Mechanical reliability; Weibull; ceramics; mechanical properties; porous materials