Effect of Pre-Treatment on Substrates for Metal Coatings Fabricated by Low Pressure Cold Spray Technique

2021 ◽  
Author(s):  
Hiroki Saito ◽  
Hiroaki Ebihara ◽  
Yuji Ichikawa ◽  
Kazuhiro Ogawa
Keyword(s):  
Low Temperature ◽  
Bonding Strength ◽  
Cold Spraying ◽  
Low Pressure ◽  
Native Oxide ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Particle Bonding ◽  
Wide Range ◽  
Pre Treatment

Abstract Low pressure cold spraying is an attractive technique for onsite metal coating fabrication due to its compactness and portability. However; the bonding strength of the coating prepared by low pressure cold spraying is generally low; which restricts the further applications in engineering and industrial fields. To improve the bonding strength; pre-treatment on substrate surface can be an effective procedure. In this study; a low-temperature plasma treatment was applied to a pretreatment technique; and the effect of the treatment on particle bonding was compared with that of a laser treatment. Copper coatings on aluminum and copper substrates were selected and studied as basic metal materials. The SEM observation results show that the particle adhesion rate significantly increases by the laser and plasma treatments; due to the removal of the native oxide films on the substrates. The particle bonding on the plasma-treated substrate reveals better interfacial adhesion with less gap compared with the laser-treated one. The pre-treatment by low-temperature plasma can be an attractive technique to assist the cold spraying process due to the oxide removal ability and no thermal effect which can apply a wide range of materials.

scholarly journals Influence of Low-Temperature Plasma Treatment on The Liquid Filtration Efficiency of Melt-Blown PP Nonwovens in The Conditions of Simulated Use of Respiratory Protective Equipment

2017 ◽  
Vol 38 (2) ◽  
pp. 195-207 ◽  
Author(s):  
Katarzyna Majchrzycka ◽  
Małgorzata Okrasa ◽  
Agnieszka Brochocka ◽  
Wiesława Urbaniak-Domagała
Keyword(s):  
Low Temperature ◽  
Plasma Treatment ◽  
Gas Flow ◽  
Filtration Efficiency ◽  
Protective Equipment ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Paraffin Oil ◽  
Wide Range ◽  
Oil Mist

Abstract Filtering nonwovens produced with melt-blown technology are one of the most basic materials used in the construction of respiratory protective equipment (RPE) against harmful aerosols, including bio- and nanoaerosols. The improvement of their filtering properties can be achieved by the development of quasi-permanent electric charge on the fibres. Usually corona discharge method is utilized for this purpose. In the presented study, it was assumed that the low-temperature plasma treatment could be applied as an alternative method for the manufacturing of conventional electret nonwovens for the RPE construction. Low temperature plasma treatment of polypropylene nonwovens was carried out with various process gases (argon, nitrogen, oxygen or air) in a wide range of process parameters (gas flow velocity, time of treatment and power supplied to the reactor electrodes). After the modification, nonwovens were evaluated in terms of filtration efficiency of paraffin oil mist. The stability of the modification results was tested after 12 months of storage and after conditioning at elevated temperature and relative humidity conditions. Moreover, scanning electron microscopy and ATR-IR spectroscopy were used to assess changes in surface topography and chemical composition of the fibres. The modification of melt-blown nonwovens with nitrogen, oxygen and air plasma did not result in a satisfactory improvement of the filtration efficiency. In case of argon plasma treatment, up to 82% increase of filtration efficiency of paraffin oil mist was observed in relation to untreated samples. This effect was stable after 12 months of storage in normal conditions and after thermal conditioning in (70 ± 3)°C for 24 h. The use of low-temperature plasma treatment was proven to be a promising improvement direction of filtering properties of nonwovens used for the protection of respiratory tract against harmful aerosols.

scholarly journals Low Temperature Plasma: A Novel Focal Therapy for Localized Prostate Cancer?

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Adam M. Hirst ◽  
Fiona M. Frame ◽  
Norman J. Maitland ◽  
Deborah O’Connell
Keyword(s):  
Prostate Cancer ◽  
Low Temperature ◽  
Focal Therapy ◽  
Localized Prostate Cancer ◽  
Low Temperature Plasma ◽  
Recurrence Rates ◽  
Novel Therapy ◽  
Temperature Plasma ◽  
Novel Approach ◽  
Wide Range

Despite considerable advances in recent years for the focal treatment of localized prostate cancer, high recurrence rates and detrimental side effects are still a cause for concern. In this review, we compare current focal therapies to a potentially novel approach for the treatment of early onset prostate cancer: low temperature plasma. The rapidly evolving plasma technology has the potential to deliver a wide range of promising medical applications via the delivery of plasma-induced reactive oxygen and nitrogen species. Studies assessing the effect of low temperature plasma on cell lines and xenografts have demonstrated DNA damage leading to apoptosis and reduction in cell viability. However, there have been no studies on prostate cancer, which is an obvious candidate for this novel therapy. We present here the potential of low temperature plasma as a focal therapy for prostate cancer.

scholarly journals Interaction model of low-temperature plasma with a steel surface during electrolyte plasma nitriding in an electrolyte on the bases of carbamide

2020 ◽  
Vol 100 (4) ◽  
pp. 39-48
Author(s):  
R.S. Kozhanova ◽  
◽  
B.K. Rakhadilov ◽  
W. Wieleba ◽  
◽  
...  
Keyword(s):  
Surface Layer ◽  
Low Temperature ◽  
Diffusion Layer ◽  
Steel Surface ◽  
Plasma Nitriding ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Near Surface ◽  
Wide Range ◽  
And Diffusion

The features of the formation of low-temperature plasma and its interaction with a metal surface were studied in this work. A qualitative model of the interaction of low-temperature plasma with the steel surface during nitriding has been developed by summarizing the available research results and taking into account the specific features of the electrolyte plasma process. In accordance with this model, in the first moments of the interaction of low-temperature plasma with the steel surface in the near-surface layer, which accelerated formation of the Feα(N) solid solution occurs due to the action of directed bombardment of charged particles, which enhances the adsorption and diffusion of nitrogen into the interior of the material, then dispersed particles of nitride of alloying elements are formed as further saturation in places with an increased level of free energy (at lattice defects, at grain boundaries, etc.). Subsequently, transformations occur in the surface zone of the layer when the limiting solubility of nitrogen in iron is exceeded, which leading to the formation of nitrides of the γ′-phase (Fe4N) and ε-phase (Fe2–3N) in it. Thus, electrolyte plasma nitriding opens up many new possibilities, in particular: varying the nitriding temperature over a wide range (400–700 ºC), targeted production of a nitrided layer consisting only of a diffusion layer without a layer of compounds, while obtaining a diffusion layer with particles γ’-phase (Fe4N) of plate form and with finely dispersed nitrides MN (CrN). The use of an electric discharge in an electrolyte (low-temperature plasma) makes it possible to increase the heating rate and diffusion saturation of the material surface. This work is of practical importance, since the studied method of electrolytic-plasma nitriding makes it possible to obtain a modified surface layer on steels with high physical and mechanical properties.

scholarly journals Direct synthesis of graphene on silicon oxide by low temperature plasma enhanced chemical vapor deposition

Nanoscale ◽  
2018 ◽  
Vol 10 (26) ◽  
pp. 12779-12787 ◽  
Author(s):  
Roberto Muñoz ◽  
Lidia Martínez ◽  
Elena López-Elvira ◽  
Carmen Munuera ◽  
Yves Huttel ◽  
...  
Keyword(s):  
Low Temperature ◽  
Silicon Oxide ◽  
Direct Synthesis ◽  
Chemical Vapor ◽  
Native Oxide ◽  
Monolayer Graphene ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Graphene Films ◽  
Free Growth

Direct, low temperature, catalyst-free and transfer-free growth of monolayer graphene films on silicon wafer with a native oxide.

Functional Properties of Electroless Silver-Plated Cotton Fabric via LTP Pre-Treatment

2008 ◽  
Vol 60 ◽  
pp. 170-175 ◽  
Author(s):  
Shou Xiang Jiang ◽  
Xiao Ming Tao ◽  
C.W.M. Yuen ◽  
C.W. Kan ◽  
L. Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Functional Properties ◽  
Cotton Fabric ◽  
Mechanical Performance ◽  
Water Repellent ◽  
Low Temperature Plasma ◽  
Silver Particles ◽  
Temperature Plasma ◽  
Plating Technique ◽  
Pre Treatment

Silver-plated textiles have exhibited their specific features not only on mechanical performance but also on functional properties. In this study, silver plating technique was applied on cotton fabric to improve its functional properties, especially the anti-bacterial and anti-UV properties. Silver plating was conducted in this research with the aid of oxygen and argon low-temperature plasma (LTP) pre-treatment on the cotton fabric to manipulate the film of the coating. The silver-plated cotton fabric was characterized in terms of its functional properties. The micro-roughness formed on the cotton fabric after the LTP pre-treatment facilitated the silver particles deposition. As a result, the anti-bacterial and anti-UV properties of the silver-plated cotton fabric and the water repellent ability of the cotton fabric were improved after the silver-plating process.

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