Spark plasma sintering (SPS) is a rapid powder consolidation technique that uses pulsed electric current to directly heat the powder. A comparison was made between the microstructural evolution of pure polycrystalline nickel powder processed by conventional (press and sinter) and SPS routes. The sintering temperature, dwell time, applied pressure and ramp rate were varied to affect the densification and microstructural evolution of the powders. Characterization of grain size, morphology, grain boundary character, and crystallographic texture was performed on SPS and traditionally-processed specimens using electron backscatter diffraction. The microstructure of SPS nickel was observed to vary between one that resembles a green body with some grain coarsening to one that is indistinguishable from a wrought nickel microstructure except for some porosity. Grain size distributions in press and sintered nickel were much wider than those for SPS nickel. SPS nickel has increased porosity at the edges, evidence of processing temperature variations.
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