Energetic Al/Ni Superlattice as a Micro-Plasma Generator with Superb Performances

Abstract

In this study, energetic Al/Ni superlattice was deposited by magnetron sputtering. A micro-plasma generator was fabricated using the energetic Al/Ni superlattice. The cross-sectional micro-structure of the energetic Al/Ni superlattice was scanned by transmission electron microscopy. Results show that the superlattice is composed of Al layer and Ni layers, and its periodic structure is clearly visible. Moreover, the bilayer thickness is about 25 nm, which consists of about 15 nm Al layer and 10 nm Ni layer. The micro initiator was stimulated using a 0.22 μF capacitor charged at 2900–4100 V. The electrical behaviors were investigated by testing the current-voltage waveform, and the plasma generation was explored by ultra-high-speed camera and photodiode. The integrated micro generator exhibited remarkable electrical exploding phenomenon, leading to plasma generations at a small timescale. The plasma outputs reflected by flyer velocities were superior to that with a much thicker bilayer of 500 nm Al/Ni multilayer. The higher flyer velocity combined with Gurney energy model confirmed the chemical reaction of the Al/Ni superlattice structure contributed to plasma production in comparison with the Al/Ni multilayers. Overall, the energetic Al/Ni superlattice was expected to pave a promising avenue to improve the initiator efficiency at a lower energy investment.

Improved Exploding Properties of Al/Cu Multilayer Initiators

“…The Al layer and Cu layer were both sputtered at 90 W. The Al/Cu multilayers contained six iterations of sputtered Al (400 nm) followed by Cu (300 nm) to appropriately obtain a stoichiometric ratio. Subsequently, a wet etch process was performed involving lithographic patterning using a positive photoresist layer to define 600 μm bow‐tie bridge regions, as described in our previous works [28]. The resulting layer has a square‐shaped bridge of 0.6 mm×0.6 mm with a resistance of 85–90 mΩ.…”

Influence of Interface Layer on the Properties of Exploding Foil Flyer Generator by Integrating Al/Ni Multilayers

“…The deposition rates for Al and Ni were about 15 and 10 nm min −1 , respectively. The remaining fabrication steps involved lithographic patterning using positive photoresist layer to define 0.6 mm square bow‐tie bridge regions, as described in our previous work . A wet etch removed the Al/Ni layers (Aluminum Etchant Type A, Transene Company, Danvers, Massachusetts).…”

“…RMFs are a significant kind of thermite nanoenergetic multilayer film. These contain a mixture of reactive films by alternative deposited on substrate (such as Al/Ni, B/Ti, Al/CuO, and Al/MnO 3 ). Lots of efforts have been devoted to explore different applications, including the initiation of subsequent reactions, thermal batteries, and localized heating for welding and joining .…”

Precisely Controlled Reactive Multilayer Films with Excellent Energy Release Property for Laser-Induced Ignition

“…In order to create a safe and efficient nonlinear exchange energy (high-energy output from low-energy input) ignitor, many researchers have tried to improve the output performance by improving the laser energy utilization and reducing the initiation threshold of the LDFPD [4, 10–12]. RMFs are a type of thermite nano-energetic multilayer film that has high energetic density and high-energy release rate [13–17]. Furthermore, the preparation of RMFs is simple, and the structure is controllable.…”

“…The output capability of the LDFPD could be improved if better materials and structures of RMFs were applied to the ablation layer of the flyer plate. An LDFPD system with RMFs has a safer and more reliable initiation than those of an electric explosive device, such as a semiconductor bridge (SCB) or an exploding foil initiator (EFI), especially in a strong electromagnetic environment [17–19]. Therefore, RMFs could be applied in the LDFPD as the ablation layer of the flyer plate to provide higher output energy and enhance the conversion efficiency of the laser.…”