Ultrasonic resonator with electrical discharge cell for ozone generation

Hybrid Plasmas for Materials Processing

“…As a result, the probability of the plasma reactive species reaching the surface before inactivation is higher when ultrasonic waves are applied, which improves surface modification efficiency. Combinations of a plasma and ultrasonic waves are investigated for understanding the interaction between plasma and acoustic waves [113][114][115], electrical discharge machining [116,117], plasma etching [118], ozone production [119][120][121][122], decomposition of volatile organic compounds (VOC) [123], charging performance improvement of corona chargers [124], and surface modification [104][105][106][107][108][109][110][111].…”

High‐speed plasma treatment of polyethylene terephthalate films using ultrasound assisted dielectric barrier discharge

“…However, mobilities of gas molecules in the vicinity of material surfaces are low, lowering the modification effect. It is reported that atmospheric pressure plasma can improve treatment effects by introducing a high‐intensity ultrasonic waves into the plasma 15,16 . It is speculated that with the ultrasound, larger percentage of reactive species can reach the surface of the material by pronounced mixing, leading improvement of the processing efficiency.…”

“…It is reported that atmospheric pressure plasma can improve treatment effects by introducing a highintensity ultrasonic waves into the plasma. 15,16 It is speculated that with the ultrasound, larger percentage of reactive species can reach the surface of the material by pronounced mixing, leading improvement of the processing efficiency. It is reported that there exists a critical sound pressure level above which mass transfer can be affected by acoustic waves based on the following semi-empirical model 17 :…”

Penetration increase of AISI 304 using ultrasonic assisted tungsten inert gas welding

“…3 Generally, two main methods are adopted to improve TIG welding penetration depth and consequently, production rate: one is to change the raw material composition by adding some minor elements into the stainless steel, such as O, S, Se and Bi, 4,5 which is of particular interest to steelmakers who supply the raw materials; the other is to change the characteristic of welding arc, which include TIG welding activated by flux [6][7][8] and the welding arc compressed by small hole in plasma welding. 9,10 The arc discharge is influenced by a wide range of different factors, such as applied voltage, electrode tip geometry, gas type and pressure, as well as the gas flow pattern and pressure distribution in the discharge region, 11,12 the last two of which can be influenced by the application of ultrasound waves. Now, ultrasonic energy has been directly led into welding pool proposed as a new method to provide continuous ultrasonic energy.…”

“…14,15 The high intensity ultrasound causes efficient mixing and forms the basis for the radial spread of the discharge, and the consequence of the radial spread of the discharge is an increase in the discharge volume. 12 The particles vibration under the ultrasonic field may increase their instantaneous velocity and their thermal conductivity. The effect of particle vibration in the arc is found to have a negligible effect in producing arc constriction and thus a higher current density to increase weld depth.…”