Master sintering curve analysis of ZnO densified by Cold Sintering Process

The Master Sintering Curve (MSC) model is traditionally used to describe the densification kinetics of a specific material and allows to determine the activation energy of the dominant mechanism. In this study, this approach is applied to the Cold Sintering Process (CSP) of ZnO with the addition of acetic acid. The result was compared with SPS sintered samples from the same dry powder. The apparent activation energy of the ZnO powder sintered by CSP with acetic acid is 4 times lower than the same dry powder (338 kJ/mol versus 83 kJ/mol). This low value confirms the low energy surface interactions between liquid and solid phases involved in mechanisms of ZnO. MSC model applied to CSP presents different interests to detect similarities or differences in sintering mechanism with different liquid phases. It allows to determine the densification trajectory of the material, then to select the optimum processing parameters to control its microstructure.