Experiment and Research of Energy Depositing Rate of Exploding Wires Under Different Initial Capacitor Voltages for Thin Film Production

摘要

Thin film produced by exploding wires is affected by many factors; one of such factors is the energy depositing rate. The research in this paper focused on measuring the voltage and current of an exploding copper wire that was 15 cm long and 0.3 mm in diameter. The time-dependent wire resistance and the energy deposited into the wire were deduced from the measured voltage and current, and the maximum wire resistance was observed at the time when part of the wire mass was heated up to the boiling point, which was called critical time and critical point, respectively. From the experiment, the following statements could be surmised: The maximum wire resistance increases from about 224.4 to 266.1 $hbox{m}Omega$, and the critical time reduces from about 8.8 to 7.2 $muhbox{s}$ when the initial capacitor voltage changes from 10 to 20 kV, as well as the fact that the mean energy depositing rate varies from about 13.3 to 27.6 $hbox{J}/muhbox{s}$ before the critical point. Also, thin copper film is prepared by this method under initial capacitor voltages of 10, 15, and 20 kV, respectively. The SEM micrographs of the film samples are also presented and analyzed. This result demonstrates that a faster energy depositing rate can help to heat up the wire mass more uniformly and more wire mass would evaporate before the critical time to create a greater wire resistance at the critical point, and the film surface is more uniform and has less void fraction.