Gas permeability and adsorbability of the glass-bonded porous silicon carbide ceramics with controlled pore size

Glass-bonded porous silicon carbide ceramics were fabricated by conventional method. The porosity and pore size could be tailored by changing the glass content and particle size of silicon carbide starting powder. The influence of microstructure on the gas permeability and the adsorption force between chucking work-pieces and porous SiC ceramic vacuum chuck was investigated. The permeability increased with the increase of porosity and average pore diameter. High permeability (1.45–6.53×10−12 m2) of the porous SiC ceramics with a porosity of 32.1–64.7% could be achieved. Compared with porosity, pore size had a dominant effect on the permeability and adsorption force. The samples with the same porosity but smaller average pore size exhibited lower permeability and much higher adsorption force. The adsorption force of porous SiC ceramics was dependent on both microstructure and permeability. The P1000V70 sample with a pressure drop (ΔP) of 0.055 MPa and permeability of 1.94×10−12 m2 exhibited the highest adsorption force of 196 N/cm2.