  An energy efficient spark plasma sintering method enabling the densification
of large size samples assisted by very low electric current levels is
developed. In this method, the electric current is concentrated in the graphite
foils around the sample. High energy dissipation is then achieved in this area
enabling the heating and full densification of large (alumina) parts ({{\O}} 40
mm) at relatively low currents (800 A). The electrothermal mechanical
simulation reveals that the electric current needed to heat the large samples
is 70 % lower in the energy efficient configuration compared to the traditional
configuration. The presence of thermal and densification gradients is also
revealed for the larger size samples. Potential solutions for this problem are
discussed. The experiments confirm the possibility of full densification (96-99
%) of large alumina samples. This approach allows using small (and low cost)
SPS devices (generally limited to 10-15 mm samples) for large size samples
(40-50 mm). The developed technique enables also an optimized energy
consumption by large scale SPS systems.
