Coalescence in cold sintering: A study on sodium molybdate

Abstract

Cold sintering (CS) is a recently developed processing technique, enabling the low temperature densification of ceramics, using a solvent and moderate pressures. Although the densification process in CS is known to be mainly driving by pressure solution creep, additional fundamental aspects driving the interfacial chemistry reactions are still a subject of debate. Herein, we focus on the aspect of grain coarsening under the densification process. Although grain coarsening by coalescence is likely to occur during CS, it becomes the dominant mechanisms after the slowdown of pressure solution creep in the late stages of the process. With sodium molybdate (Na2Mo2O7) as model material, and using water as a transient phase, we investigate the evolution of features confirming coalescence as one of the mechanisms operating during cold sintering.

Keywords

• Cold sintering
• Mechanisms coalescence
• Pressure solution
• Ceramics