Second Discharge Characteristics of Aluminum Wire Electrical Explosion Under Various Argon Pressures

Electrical wire explosion is a promising method for the preparation of metal nanopowder, but the properties of metal nanopowder are affected by the second discharge process of electrical wire explosion. The second discharge characteristics of aluminum wire electrical ex- plosion under variant argon pressures were studied in a RLC discharge circuit. The results show that the curve of the second discharge voltages versus the pressure presents a U-shape. To clarify the roles of aluminum vapor and argon in the process of the second discharge, a spectrograph and a high speed framing camera were used to study the radiation spectrum and spatial distribution of the electrical explosion plasma. It is observed that argon participates in the second discharge process under low pressure. A discharge channel develops along the surface of the aluminum vapor. Under higher pressure, a second discharge takes place in the aluminum vapor and the discharge channel is inside the aluminum vapor.