An investigation into the parameters affecting the breakdown voltage and inter-particle bonding in the electrical discharge compaction of metal powders

The aim of present investigation is to gain deeper understanding of breakdown behavior and inter-particle bonding by conducting experimental tests. This may lead to improve the state of compaction by relative arrangement of initial parameters to maintain uniform distribution of current density and producing compacts with sufficient mechanical strength. Experimental work was carried out using two different set-ups. The first arrangement was employed to provide steady-state alternating voltage. The effect of column geometry and particle size on breakdown voltage was investigated under this condition. The second set-up, capacitor discharge circuit, was used to provide impulse voltage. Under this condition, the influence of column geometry, particle size, application of axial pressure, evacuation of air, energy input, electrode material and configuration on breakdown voltage was studied. Also, scanning electron microscopy was employed to study the effect of different parameters on inter-particle bonding. The results of experiments conducted on the influence of each of the voltage and capacitance on the compaction properties are also discussed.