Thermal Conductivity and Microstructure Properties of Porous SiC Ceramic Derived from Silicon Carbide Powder

Abstract

Porous SiC ceramic were prepared with silicon carbide powder as the aggregate, silicone resin as the binder and pore agent by the process of mixing, iso-static pressure molding, and calcination. The mechanical properties and microstructures of the samples were characterized with a universal testing machine, X-ray diffraction, scanning electron microscope, and mercury injection. Two main factors, molding pressures and silicone resin mass ratio were studied in the experiments. The thermal conductivity of the samples was tested. The compressive strength was up to 19.4 MPa, and the porosities up to 30%. The thermal conductivities, mainly influenced by porosities, increased from 0.68 W·m ·K−1 with the porosity decreasing from 41.96% to 31.30%.

Porosity estimation of Phyllostachys edulis (Moso bamboo) by computed tomography and backscattered electron imaging

“…Therefore, the skeletal density of the Moso bamboo is higher than this value. The fraction variation of the phases leads to the variations in other hydrothermal properties (Wu et al 2013).…”

Preparation of porous SiC ceramics for thermal dissipation purposes

“…In order to reduce the firing temperature, several reactionbonding processes have been developed to prepare porous SiC at relatively lower temperatures [6][7][8][9][10][11][12][13][14]. These processes started with the mixing of various bonding agents with SiC particles.…”

“…The firing was carried out either in air or in an inert environment. During firing at elevated temperatures, the bonding agents reacted with silica on the surface of the SiC particles to form either mullite [6][7][8][9]13] or silicate [9][10][11][12]14]. The strength of these porous SiCs varied from 3 to 185 MPa, depending on the type and amount of the bonding materials used.…”

“…The limited data available shows that the thermal conductivity of the porous SiC is relatively low. In addition, when the porous SiC bonded with the silicone resin, the thermal conductivity drops to only 1 W/m K [10]. Therefore, it is of interest to develop porous SiC with both high strength and high thermal conductivity for thermal dissipation purposes.…”

Purification and particle size control of β-SiC powder using thermocycling process

“…Because of these superb mechanical properties, SiC has been drawing attention as a structural ceramic material. [1][2][3] In addition, SiC single crystals have been considered as alternative semiconducting materials replacing silicon since they have a wide band gap and good thermal stability. 4,5 SiC powders can be produced using various methods such as carbothermal reduction of silica, direct carbonisation 6 of Si metals and pyrolysis of silane compounds.…”