Particle Size Control of Nanosize Powders Synthesis by Pulsed Wire Discharge

Abstract

In this research, nanosized powders of copper were synthesized by pulsed wire discharge at 100 Torr and 800 Torr of nitrogen gas. And the particle size distributions of the powders were evaluated by SEM observations. The results showed that the particle diameters of peak counts were 30 nm and 45 nm at pressures of 100 Torr and 800 Torr, respectively. However, the number of submicrometer-sized particles was fewer in the powder synthesized at 800 Torr than that at 100 Torr. The energy deposition in the wire was 38 J at 100 Torr, and 52 J at 800 Torr, respectively. Even though discharge energy was 135 J, which is twice of energy then required for vaporizing the wire (∼67 J) , the energy deposition at both pressures were lower than the vaporization energy.