View article

Cold sintering process (CSP) combines transient liquid phase and/or external pressure to assist the densification of ceramics, the sintering mechanism of which is typically dominated by the “dissolution–precipitation” process. In this work, Na₂WO₄·2H₂O dry powders without liquid water have been used as the “liquid phase” to realize the densification of Na₂WO₄ ceramics. The effects of sintering parameters on the CSP of Na₂WO₄ ceramics using Na₂WO₄·2H₂O dry powders are systematically studied, including sintering temperature, external pressure, sintering process time and the amount of Na₂WO₄·2H₂O phase. It is found that the “liquid phase,” that is, Na₂WO₄·2H₂O is the key factor for controlling the CSP of Na₂WO₄ ceramics, and Na₂WO₄·2H₂O hydrate shows an advantage of homogeneous dispersion of liquid water. The sintering temperature affects the densification mechanism involved with plastic …