The effect of electric field and pressure on the synthesis and consolidation of materials : A review of the spark plasma sintering method

The use of electric current to activate the consolidation and reaction-sintering of materials is reviewed with special emphasis on the spark plasma sintering (SPS) method. The method has been used extensively over the past decade with results showing clear benefits over conventional methods. The review critically examines the important features of SPS and their individual roles in the observed enhancement of the consolidation process and the properties of the resulting materials. These features include a high heating rate, the application of pressure, and the effect of the current. The intrinsic contributions of the current to mass transport have not been well studied, but their role in SPS and non-SPS processes has recently been shown. The role of plasma in SPS is unclear. 156 refs.