Innovative multi-stage spark plasma sintering to obtain strong and tough ultrafine-grained ceramics

This paper reports how a multi-stage spark plasma sintering (SPS) schedule can be successfully adopted to consolidate ultrafine-grained ceramics with uniform and better mechanical properties than the widely studied single-stage SPS schedule. To date, a major concern in the materials community is that rapid heating and shorter holding in the single-stage SPS process causes inhomogeneous radial/axial temperature distribution, which is consistent with a number of computational studies. Our new approach to developing better ceramics is expected to address this concern.