Recent Development of Pulse Electric Current Sintering Mechanism

Pulse electric current sintering (PECS) is a new rapid sintering approach. A variety of materials such as metal, ceramics, composite and functionally graded materials have been prepared. PECS apparatus is somewhat like a conventional hot-press apparatus. It is characterized by the application of a pulse electric current and/or a direct current as the power and by the graphite mold and punches acting as heating elements. Much attention has been paid to investigate the sintering process of PECS from different standpoints. In the sintering of metallic (copper) powder, pulse current is effective in promoting the densification of copper powder compacts because pulse current passes through both the graphite mold and the powder compact. In the sintering of non-metallic (Al2O3) powder, the densification of Al2O3 powder is due to heat transfer from the graphite mold and punches. Heating rate of PECS is high by the application of a large electric current and heat transfer is efficient by using the graphite mold and punches as heating elements. Therefore, rapid sintering is made possible.