Modeling the effect of pulsing on the spark plasma sintering of silicon nitride materials

The effect of the pulse peak voltage on the initial particle rearrangement stage of liquid-phase spark plasma sintering of silicon nitride is studied by varying the DC on:off pulse pattern. The shrinkage rate vs. temperature curves showed that the intensity and position of the rearrangement stage peak were dependent on the pulse peak voltage. An alternative sintering mechanism based on the electrowetting phenomenon is proposed to explain the experimental data.

► Modeling the effect of pulsing on the liquid-phase spark plasma sintering.
► Experimental evidence of electrowetting during the SPS of Si3N4.
► Pulse peak voltage is a key parameter affecting rearrangement shrinkage rate.
► Model fits the dependence of the maximum shrinkage temperature with pulse peak voltage.
► Model fits the dependence of the relative shrinkage rate with pulse peak voltage.