Tape casting is a well-established technique to fabricate ceramic tapes. This technique has been usually applied to produce dense substrates for electronic applications, but recently there are increasing efforts regarding the production of porous cast tapes. The aim of this paper is to present the latest strategies and achievements to manufacture porous ceramic materials by tape casting. The pores morphology can be manipulated by adjusting particle size, sacrificial pore formers, sintering conditions, and combined techniques (phase inversion and freeze casting). Moreover, tape casting enables adjusting the thickness of the product, which is a key property in separation applications using membranes and/or support materials with tailorable structure.

Manufacturing porous ceramic materials by tape casting—A review

Eggplant-derived SiC aerogels with high-performance electromagnetic wave absorption and thermal insulation properties

A novel light but strong SiC foam with hierarchical porous architecture was fabricated by using dough as raw material via carbonization followed by carbothermal reduction with silicon source. A significant synergistic effect is achieved by embedding meso- and nanopores in a microsized porous skeleton, which endows the SiC foam with high-performance electromagnetic interference (EMI) shielding, thermal insulation, and mechanical properties. The microsized skeleton withstands high stress. The meso- and nanosized pores enhance multiple reflection of the incident electromagnetic waves and elongate the path of heat transfer. For the hierarchical porous SiC foam with 72.8% porosity, EMI shielding can be higher than 20 dB, and specific EMI effectiveness exceeds 24.8 dB·cm3·g–1 at a frequency of 11 GHz at 25–600 °C, which is 3 times higher than that of dense SiC ceramic. The thermal conductivity reaches as low as 0.02 W·m–1·K–1, which is comparable to that of aerogel. The compressive strength is as high as 9.8 MP...

Light and Strong Hierarchical Porous SiC Foam for Efficient Electromagnetic Interference Shielding and Thermal Insulation at Elevated Temperatures

Atomic layer deposition (ALD) is a technology offering the possibility to prepare thin films of high quality materials on high aspect ratio substrates with precise thickness control, high uniformit...

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Atomic Layer Deposition for Membranes: Basics, Challenges, and Opportunities

The directional freezing of microfiber suspensions is used to assemble highly porous (porosities ranging between 92% and 98%) SiC networks. These networks exhibit a unique hierarchical architecture in which thin layers with honeycomb‐like structure and internal strut length in the order of 1–10 μm in size are aligned with an interlayer spacing ranging between 15 and 50 μm. The resulting structures exhibit strengths (up to 3 MPa) and stiffness (up to 0.3 GPa) that are higher than aerogels of similar density and comparable to other ceramic microlattices fabricated by vapor deposition. Furthermore, this wet processing technique allows the fabrication of large‐size samples that are stable at high temperature, with acoustic impedance that can be manipulated over one order of magnitude (0.03–0.3 MRayl), electrically conductive and with very low thermal conductivity. The approach can be extended to other ceramic materials and opens new opportunities for the fabrication of ultralight structures with unique mechanical and functional properties in practical dimensions.

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Santosh Raju

Papers

Processing and properties of macroporous silicon carbide ceramics: A review