Open AccessEffective Thermal Conductivity for Low Density Silicon Nitride Porous Ceramics
Author(s) -
Chen Bi,
Yuan Lu,
Yating Xu
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1681/1/012003
Subject(s) - thermal conductivity , materials science , thermal conduction , porosity , silicon nitride , heat transfer , ceramic , composite material , porous silicon , thermal diffusivity , thermal insulation , thermal transmittance , nitride , thermal resistance , thermodynamics , layer (electronics) , physics
Thermal conduction in porous materials generally includes four heat transfer forms, i.e. heat transfer via the gas phase, heat conduction along the solid matrix/skeleton, thermal radiation and gas-solid coupled heat transfer. The size effects on the gas and solid thermal conductivities are introduced to predict the effective thermal conductivity of the silicon nitride porous ceramic at room temperature, and the predictions from the random model present good agreements with the experimental data. The effect of the porosity on the effective thermal conductivity of the low density silicon nitride porous ceramic are studied as well, and the low density porous ceramics can achieve a low thermal conductivity in the range of 0.08-1.2 W/m K for a good performance of thermal insulation.