A discussion on the absence of plasma in spark plasma sintering

Spark plasma sintering (SPS) is a remarkable method for synthesizing and consolidating a large variety of both novel and traditional materials. A number of mechanisms have been proposed to account for the enhanced sintering abilities of the SPS process. Of these mechanisms, one commonly put forth, and the one that draws the most controversy, involves the presence of momentary plasma generated between particles. This experimental study and subsequent discussion advocates the absence of plasma during SPS.