Low sintering shrinkage porous ceramics: Principles, progress, and perspectives

Porous ceramics are lightweight materials with diverse pore structures, finding wide applications in areas such as thermal insulation, sound absorption, filtration, catalysis, and energy storage. However, excessive shrinkage during the sintering process of porous ceramics leads to cracking and deterioration, posing significant challenges for achieving complex shape. Despite its importance, the field of low sintering shrinkage porous ceramics has not received sufficient attention. This review systematically discusses the principles and progress in the development of low sintering shrinkage porous ceramics. Firstly, we introduce the characteristics of various preparation methods, including partial sintering, particle-stabilized foaming, gel-casting, foam gelcasting, and additive manufacturing. We then explain three primary principles of low sintering shrinkage from the perspectives of volume effect and mass transfer processes. The review focuses on the properties and applications of typical low sintering shrinkage ceramics such as mullite and alumina, particularly their mechanical properties and thermal conductivity as thermal insulation and ceramic cores. Finally, we summarize the current state and present future perspectives on low sintering shrinkage porous ceramics.