A disc of a composite ceramic material composed of silicon nitride (Si3N4) and 20% hBN was prepared and its tribological characteristics were investigated by sliding a Si3N4 pin across its surface at different sliding speeds. The friction coefficient and wear coefficient were determined for the composite using two different test modes: one in which the pin was kept stationary and the disc was rotated on top of the pin, ...
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 ...
Ambient pressure dried hydrophobic silica aerogel monoliths were prepared via simultaneous solvent exchange and surface modification in order to minimize volume shrinkage and density. At room temperature, the obtained silica aerogels had a low density of 0.096 g/cm3, a high surface area and hydrophobicity, and a low thermal conductivity of 0.0217 W/m·K. The effect of heating on these properties was also determined. After the aerogel had been heated to 300...
A porous matrix was prepared using low-density sawdust and a metakaolin-based geopolymer paste. The matrix was prepared in order to evaluate its performance as a thermally insulating building envelope. The matrices that had approximately 4 MPa of bi-axial four points flexural strength were prepared in a ratio of geopolymer paste:sawdust of between 1:1 and 1:1.5, and the thermal conductivity of these matrices was between 0.2-0.3 W/m·K....
Styrene-butadiene (SBR) was added to high-density polyethylene (HDPE) to form a polymer blend. The thermal conductivity and thermal diffusivity of this polymer blend at room temperature were determined at varying blend compositions. The effects of dynamic crosslinking with sulfur crosslinking system and a mixed system on the thermal conductivity and diffusivity were also investigated. Finally, different models were evaluated for the estimation of thermal conductivity of a two phase system....
