Functionally graded composite ceramics: design, manufacturing, properties and applications

Functionally graded ceramics (FGCs) are a class of advanced ceramic materials with spatially varying composition, phase or microstructure, designed to achieve continuous or discrete variations in material properties through advanced techniques. They have played a crucial role in replacing conventional ceramic materials in advanced applications as a function of its superior performance in balancing mutually exclusive properties (toughness and strength etc.). Herein, we apply towards comprehensively discuss the emerging advancements in FGCs, highlighting their design, manufacturing, properties and applications. Different design principles were discussed from structural design, stress design, composition design to computer-aided design. Furthermore, in-depth perspective analysis of advanced processing technologies was summarized including powder metallurgy, slip casting, and additive manufacturing. Additionally, the thermal and mechanical properties of FGCs were summarized, accompanied by the corresponding property enhancement mechanisms. Finally, the critical challenges and potential applications in further developing functionally graded ceramics were provided. This comprehensive overview of FGC would be referenceable and helpful to the researchers working in this area or new-come to this field, thereby identifying the research gaps for advancing the field.