Electric pulse consolidation: an alternative to spark plasma sintering

This article includes a comprehensive review of the methods of sintering of powder materials based on the use of electric current as a technological tool and presenting alternatives to the spark plasma sintering technique. The described sintering methods utilize electric discharges of several kilovolts (as opposed to low-voltage processing employed by spark plasma sintering), electric current densities exceeding 10 kA cm−2, and pressures of up to 10 GPa. In most cases, the powder to be consolidated is subjected to a single electric pulse of short duration (shorter than 0.1 s). The general term used to refer to these methods is electric pulse sintering (EPS). At present, the methods of EPS are rapidly advancing, which stimulates the development of their technical capabilities and equipment. This review provides a description of the facilities used by research groups in different countries. The EPS set-ups vary by the type of electric pulse generator, pressing equipment, geometrical features of the working chambers, die materials, as well as by other elements of design making each set-up unique among similar ones. In the paper, in addition to the practical technological aspects, the main physical processes occurring during EPS are described. The mechanisms of sintering as well as the influence of sintering parameters on the quality of the compacts are also discussed. Possibilities of using EPS for the production of high-strength materials, complex composite materials, nanostructured materials, and metal–ceramic composites are shown.