Processing and properties of macroporous silicon carbide ceramics: A review

Macroporous silicon carbide is widely used in various industrial applications including filtration for gas and water, absorption, catalyst supports, concentrated solar power, thermoelectric conversion, etc. During the past several years, many researchers have found diverse routes to fabricate macroporous SiC with porosity ranging from 9% to 95%. This review presents a detailed discussion on processing techniques such as partial sintering, replica, sacrificial template, direct foaming, and bonding techniques, as well as the mechanical and thermal properties of macroporous SiC ceramics fabricated using these methods. The full potential of these materials can only be achieved when properties are tailored for a specific application, whereas the control over these properties is highly dependent on the processing route. From the collected data, we have found that the porosity ranges from 9% to 91% with flexural strength of 1–205 MPa, compressive strength of 1–600 MPa, fracture toughness of 0.3–4.3 MPa m1/2, and thermal conductivity of 2–82 W/(m·K). This review will enlighten future investigations on processing of porous SiC and its usage in various applications.