Si-SiC composite foams were prepared using tannin-based foams as templates. The foams were prepared by four different methods for the determination of which method would best produce a foam with a pore size under 200 µm. The foam samples were characterized by SEM, XRD, and Raman spectroscopy, and the thermal conductivity of one of the foams was investigated by the transient plane source method. It was found that direct infiltration of ...
Author(s): A. Ortona, Alain Celzard, Antonio Pizzi, C. Zollfrank, G. Amaral-Labat, S. Pusterla, V. Fierro
Composite silica aerogels were prepared using sodium silicate and ceramics fibers. The thermal conductivities of these composites were investigated to determine how effective they would be as thermal insulation. As temperature increased to 400oC, the thermal conductivity of these composites only increased from 0.0266 to 0.0572 W/(m·K). This indicates that these composites which have good structural and mechanical properties would be good thermal insulators during thermal processes....
Author(s): Liu Guangwu, LiuYangang, Ni Xingyuan
This article discusses the creation of a porous mullite ceramic through the incorporation of fly ash cenospheres (FAC) into mullite powder through the gelcasting process. Sintering temperature and the amount of FAC added were investigated as factors affecting density and strength. The authors found that the porous mullite ceramics had a high strength, and high porosity (48.1-72.2%) Thermal conductivity was measured and was determined to be 0.16-0.22 W/mK....
Author(s): Haoran Qian, Heping Zhang, Ruifang Zhang, Xudong Cheng, Yonghong Wang
The effects of solid phase thermal conductivity, pore thermal conductivity, and pore volume fraction on the measured effective thermal conductivity of porous ceramics with pore volume fractions of 4 to 95% were investigated. The experimental results were then compared with pre-existing numerical models. It was found that the Maxwell-Eucken relation for closed porosity and the Landauer relation for open porosity were able to closely predict the effective thermal conductivity for tin oxide, ...
Author(s): Arnaud Alzina, Benoit Nait-Ali, David S. Smith, Fabienne Pennec, Hideaki Matsubara, Julie Bourret, Kodai Otsu, Nicolas Tessier-Doyen, Pierre Elser, Urs T. Gonzenbach
Traditionally, white LED's are made by mixing phosphor with an epoxy resin. But, the phosphor is not always evenly distributed, and the epoxy resin has a low thermal conductivity resulting in accelerated thermal aging during operation. This article studies the effects of implementing a ceramic phosphor plate with varying concentrations of magnesium oxide, and silicon dioxide. It was found that as the magnesium oxide concentration increased so did the thermal ...
Author(s): Byung Woo Jeong, Dae-Ho Yoon, Eun-Kyung Ji, Mong Kwon Jung, Sang Hwan Bak, Young-Hyun Song
