Calibration method of driving energy for vaporizing foil actuator welding and its application

In this study, a driving energy calibration method applicable to the vaporizing foil actuator (VFA) was proposed and applied to the process of vaporizing foil actuator welding (VFAW). This method is based on a technical approach combining high-speed photography with finite element simulation: the corresponding relationship between the driving velocity and actual driving energy was established via simulation, and then the actual driving energy was derived by inversion, according to the driving velocity measured by high-speed photography. Based on the established VFA driving energy model, the enhancement effect of the water medium on the driving capacity of VFA was quantitatively revealed for the first time, with an average improvement of approximately 61.5%. Furthermore, it was analyzed that about 50% of this gain is attributed to the “medium effect” of water. Finally, the calibrated driving energy was applied to the full-process numerical modeling of VFAW, enabling the morphology prediction of the welding interface in standoff-free VFAW. The results show that the interface morphology, wave characteristics, and weld width obtained from the simulation are in good agreement with the observations by scanning electron microscopy, which verifies the reliability of the established full-process simulation model. The proposed energy calibration method can offer theoretical guidance for VFAW process optimization and interface morphology prediction.