Nontoxic Processing of Reliable Macro-Porous Ceramics

A direct-foaming technique to produce macro-porous ceramics is presented considering three key aspects: (i) a processing route without toxic additives, (ii) optimizing particle packing and dispersion of ceramic suspensions to obtain denser struts, and (iii) processing reliability for large-scale production. To achieve the latter goal, specific foaming equipment was designed. Ceramics with large dimensions (250 x 60 x 110 mm(3)), high porosity level (>70%), homogeneous and narrower pore-size distribution, high Weibull modulus (8 to 11), improved mechanical strength (3 to 15 MPa) for different compositions and low thermal conductivity at 1200 degrees C (0.3 to 0.9 W/mK) were attained.