Preforming of Metal—Polymer Composites by Electrical Discharge Compaction of Powders

Abstract

Preforms of metal-polymer composites are produced by high voltage electrical discharge compaction (EDC). A relatively low density preform is obtained by simply connecting the powder mix, contained in a tube, across a charged capacitor bank. Above a certain voltage the oxide layers of the metal particles are broken and a heavy transient current passes through the powder column. Owing to combined electrothermal and electromagnetic effects, the powder mix consolidates into a preform in a period of ~50 μS. There is an upper level for the discharge voltage beyond which the powder column disintegrates like an exploding fuse wire. In the present paper, the EDC process is investigated with special emphasis on the effect of percentage content of low density polyethylene powder on the compaction of plain carbon steel powder. PM/0457