Atmospheric Plasma Processing Research Articles

Superhydrophobic CFxCoating via In-Line Atmospheric RF Plasma of He−CF4−H2

Stable superhydrophobic coatings on various substrates are attained with an in-line atmospheric rf plasma process using CF4, H2, and He. The coating layer is composed of CFx nanoparticulates and has an average roughness of approximately 10 nm. This roughness is much smaller than other surfaces reported for superhydrophobicity in the literature. The superhydrophobic coatings are produced on both metallic and insulating substrates without any need of separate microroughening or vacuum lines.

Synthesis and characterization of hard metal coatings by electro-plasma technology

Electro-plasma technology (EPT) is a cathodic atmospheric plasma process which has shown great promise for the deposition of metal coatings exhibiting excellent adhesion to the substrate along with high deposition rates. The present study involves synthesis and characterization of molybdenum coatings using EPT processing. The morphology, composition and structure of Mo-coated surfaces were characterized. The results indicate the successful deposition of molybdenum, with molybdenum alloyed into the surface of both the 4330V steel and Inconel 718 substrates. The surface morphology and roughness of the coated samples reflect unique EPT-induced micro-roughness features. Superposition of the EPT-induced micro-roughness profile on the macro-roughness profile of the substrate surface provides the potential to improve adhesion characteristics of surface. An increase in hardness observed on Mo-coated steel indicates potential to produce hard surfaces by EPT, leading to many advanced applications.

Dynamic plasma processing and non-stationary heating of surface at interaction with pulse atmospheric plasma

The principle of action of the device generating the pulse high-frequency category, allowing is considered to create at atmospheric pressure plasma with the form of long string. The recommendations for use and research of the given atmospheric plasma process for the maximal activation and clearing of dielectric polymeric surfaces are given.

Mechanical and precorroded fatigue properties of coated aluminium aircraft skin system as function of various thermal spray processes

Aluminium coatings deposited on AA2024-T3 by the flame arc, atmospheric plasma and high velocity oxyfuel (HVOF) processes were evaluated using quantitative metallography, microhardness, adhesion, three point bend and conventional fatigue tests as well as fatigue tests on precorroded samples. Comparison of the microstructures, mechanical properties, and the fatigue and precorroded fatigue properties of samples with the three types of thermal spray coating, as well as samples of bare AA2024-T3 and Alclad AA2024-T3, revealed that HVOF is the most promising thermal spray process for the deposition of aluminium coatings, and, in particular, HVOF coatings greatly increase the fatigue and precorroded fatigue lifetimes of the AA2024-T3 substrate.

Physics and chemistry in a glow dielectric barrier discharge at atmospheric pressure: diagnostics and modelling

Glow dielectric barrier discharge (GDBD) appears as an attractive solution to realise an atmospheric pressure cold plasma process suitable for all the surface treatments including thin film coatings. Such a development requires a large understanding of the GDBD physics and chemistry. The objective of this work is to contribute to that understanding. From the analysis of electrical measurements, time resolved emission spectroscopy, short exposure time pictures and numerical model results, it is shown that GDBD which are discharges due to a Townsend initiation and not to a streamer coupling, transit from Townsend to subnormal glow discharge during the current increase. Depending on the maximum current density, they can be considered as a glow or a Townsend discharge. In a glow discharge, the memory effect from one discharge to the following one is based on electrons and ions trapped in the positive column while in a Townsend discharge, it is metastables which stay in the gas and create electrons through cathode secondary emission. In all the cases, the ionisation has to be slowed down by a significant contribution of Penning ionisation.

Radio frequency hollow cathode source for large area cold atmospheric plasma applications

A new type of radio frequency (rf) large area non equilibrium (‘cold’) plasma source operating at atmospheric gas pressures in an open reactor was presented. The source was based on a specially designed rf electrode with the gas flowing through an inner microstructure integrated in the electrode. A cylindrical source of 35 mm in diameter with approximately 900 hollow cathodes forming an integrated open structure and a rectangular 120×20 mm 2 source of this type were tested. A typical rf power for the source operation is only several tens of watts. Experiments show that the performance of both sources at atmospheric pressure was substantially better in comparison with single cylindrical rf hollow cathodes of 400 μm in diameter. The argon and neon plasmas generated in the space between the main electrode and the substrate holder were uniform and very stable. The optical emission spectroscopy study, the rf current, voltage and impedance measurements, as well as the substrate temperature tests reveal three different power dependent regimes of these plasma sources. Effects of plasma treatment of surfaces were studied on both temperature sensitive samples (plastic webs) and metals (aluminum, steel). An effective cleaning of Al samples was observed after 5 min treatment in the neon plasma in an open reactor. After 1 s treatment of the Polyethylene web the surface tension increases from values<34 mN/m to values ⩾56 mN/m. Design of sources allows their direct scaling up and may bring a number of interesting applications in large area cold atmospheric plasma processing.

大気圧プラズマと表面処理プロセス 大気圧非平衡プラズマプロセシングの特徴

大気圧プラズマと表面処理プロセス 大気圧非平衡プラズマプロセシングの特徴

大気圧プラズマと表面処理プロセス 導電セラミックスをトリガーとする大気圧非平衡プラズマプロセシング

大気圧プラズマと表面処理プロセス 導電セラミックスをトリガーとする大気圧非平衡プラズマプロセシング

Low temperature atmospheric pressure discharge plasma processing for volatile organic compounds

Abstract The 1,000 ppm VOCs (volatile organic compounds) decomposition performance of SPCP (Surfaced Discharge Induced Plasma Chemical Processing) was studied relating to various carrier gas effects, plasma exposing methods and others in order to understand the decomposition mechanisms. In any carrier gas, a direct SPCP can decompose every VOC tested. The efficient decomposing carrier gases are oxygen, air and nitrogen in that order. However, when the SPCP treated gasses (air, nitrogen or oxygen) are mixed with contaminated gasses, oxygen seems be necessary to decompose VOCs. Four new halogenated (chloro-)organic materials are also tested as contaminants. The maximum decomposition for every contaminants is found to be more than 90% and the energy efficiency for each contaminant is roughly in the same order.