Consolidation of iron powder by electrical discharge

Abstract

Capacitor electrical discharge consolidation (CEDC) is a technique that uses the heat of the Joule effect of a high intensity electric current to consolidate powders. In this study, the effect of the precompaction pressure and the number of discharges on the porosity, microstructure and hardness of the compacts is analysed. Furthermore, the sintering results of iron powders obtained through the conventional route (cold pressing and furnace sintering) and by CEDC are compared. Experiments show that at low initial pressures the powder column has the necessary resistance to produce the joule heat necessary for powder consolidation. At an initial pressure of 200 MPa the porosity of the specimens decreases from 0.32 to 0.24, and the Vickers microhardness increases from HV10 29 to HV10 51 after 50 discharges.