Low-Temperature Fabrication of Ceramics by the Cold Sintering Process

Sintering transforms a shaped powder compact into a dense solid by applying high temperatures, typic ally >1000 °C. It is a vital step in the fabrication of ceramics, which dictates the microstructure, and hence, the final structural and functional properties of the sintered parts. However, the application of high temperatures poses several challenges for ceramic manufacturing including: I) high energy consumption and carbon footprint, II) loss of volatile elements, resulting in the degradation of functional properties, III) grain growth and limited microstructural control, and IV) limited materials integration possibilities for composite systems. Therefore, novel sintering techniques that can lower the sintering temperature have attracted the focus of recent research. The recently developed Cold Sintering Process (CSP) (Fig. 1) has successfully enabled ultralow-temperature densification of ceramics at temperatures below 350 °C by utilising chemical pathways and applied pressure.