1. Thermal conductivity of porous materials
- Author
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Kodai Otsu, Arnaud Alzina, Julie Bourret, Hideaki Matsubara, Fabienne Pennec, Benoît Nait-Ali, Nicolas Tessier-Doyen, David S. Smith, Urs T. Gonzenbach, Pierre Elser, Groupe d'Etudes des Matériaux Hétérogènes (GEMH), Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Axe 1 : procédés céramiques (SPCTS-AXE1), Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM), Nagoya Institute of Technology (NIT), Japan Fine Ceramics Center (JFCC), and Collaboration NITECH - Japan
- Subjects
010302 applied physics ,Materials science ,Mechanical Engineering ,Aluminate ,02 engineering and technology ,[CHIM.MATE]Chemical Sciences/Material chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,chemistry.chemical_compound ,Thermal conductivity ,Volume (thermodynamics) ,chemistry ,Mechanics of Materials ,Phase (matter) ,0103 physical sciences ,Volume fraction ,General Materials Science ,Composite material ,0210 nano-technology ,Porosity ,Porous medium - Abstract
International audience; Incorporation of porosity into a monolithic material decreases the effective thermal conductivity. Porous ceramics were prepared by different methods to achieve pore volume fractions from 4 to 95%. A toolbox of analytical relations is proposed to describe the effective thermal conductivity as a function of solid phase thermal conductivity, pore thermal conductivity, and pore volume fraction (νp). For νp < 0.65, the Maxwell–Eucken relation for closed porosity and Landauer relation for open porosity give good agreement to experimental data on tin oxide, alumina, and zirconia ceramics. For νp > 0.65, the thermal conductivity of kaolin-based foams and calcium aluminate foams was well described by the Hashin Shtrikman upper bound and Russell’s relation. Finally, numerical simulation on artificially generated microstructures yields accurate predictions of thermal conductivity when fine detail of the spatial distribution of the phases needs to be accounted for, as demonstrated with a bio-aggregate material.
- Published
- 2013