Water-augmented vaporizing foil actuator welding: Process performance and mechanisms clarifications

This paper proposes a novel impact welding method named water-augmented vaporizing foil actuator welding, in which liquid water is introduced to alter the foil's vaporization process, thus altering the induced driving pressure and the final welding performance. A series of comparative experiments were performed to confirm the effectiveness of the process and to understand the underlying mechanism. The proposed process decreased the lower-bound required discharge energy by 58-69%, increased the peel strength by 30-60%, and significantly reduced the variability in the critical standoff distance at the lower bound of the weld window. In addition, the proposed process resolved the robustness issue by producing a much more regular and repeatable shape of the weld area compared to conventional VFAW. Furthermore, three potential mechanisms have been proposed to explain the process improvement: the added water 1) increased the electrical energy deposition, 2) introduced additional energy from the aluminum-water chemical reaction, and 3) provided a more efficient force-transfer medium. In summary, this paper introduces a novel impact welding method with much improved process capability and robustness compared to conventional vaporizing foil actuator welding. In addition, due to its simplicity, this method may be easily extended for other forms of impulse metalworking, which may stimulate a wide interest for the community of high velocity metalworking.

Automated summary

This paper proposes a novel impact welding method called water-augmented vaporizing foil actuator welding, which introduces liquid water to alter the foil's vaporization process and improve the welding performance. Comparative experiments confirm that the proposed process reduces energy requirements, increases peel strength, and improves the stability of the weld window. Three potential mechanisms, including increased electrical energy deposition, additional energy from the aluminum-water reaction, and a more efficient force-transfer medium, are proposed to explain the process improvement. In summary, this paper introduces a new impact welding method with improved process capability and robustness, which may stimulate interest in the community of high velocity metalworking.