• Composites Research
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• v.25 no.6
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• pp.198-204
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• 2012

The objective of this study is to improve the mechanical properties in abaca fabric/epoxy composites produced using a VARTM process. The mechanical properties were improved by increasing the surface roughness of the fabric through plasma polymerization and improving the interfacial adhesion between the epoxy and the fabric through changing its hydrophilic properties to the hydrophobic properties. Plasma polymerization at atmospheric pressure and room temperature was used, and the optimal polymerization time to improve the mechanical properties was investigated. NaOH treatment on the fabric was also carried out for the comparison. The composite fabricated using the fabric polymerized for 10 seconds shows the highest tensile strength compared to that of none-polymerized or NaOH treated. Plasma polymerization for more than 20 seconds exhibits decrease in the tensile strength. As a result, the plasma polymerization for more than 20 seconds may have caused some damages on the surface of the fabrics. Also, the hydrophilic abaca represents a tendency of presenting the hydrophobic properties in absorption and sedimentation tests.

• Elastomers and Composites
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• v.37 no.2
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• pp.99-106
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• 2002

In this work, the surface properties and mechanical interfacial properties of the carbon blacks treated by oxygen plasma were investigated. The surface properties of carbon black by oxidation process of oxygen plasma were studied in acid-base surface value, zeta potential, and X-ray photoelectron spectroscopy (XPS). And their mechanical interfacial properties of the carbon black/rubber composites were evaluated by the composite tearing energy ($G_{III}c$). As a result, it was found that the introduction rate of oxygen-containing polar functional groups, such as carboxyl, hydroxyl, lactone, and carbonyl groups, onto the carbon black surfaces was increased by increasing the plasma treatment time. It revealed that the polar rubber, such as acrylonitrile butadiene rubber (NBR), showed relatively a high degree of interaction with oxygen-containing functional groups of the carbon black surfaces, resulting in improving the tearing energy ($G_{III}c$) of the carbon black/acrlyonitrile butadiene rubber composites.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.200.1-200.1
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• 2016

Tungsten coatings on the graphite (CX-2320) were successfully deposited using the vacuum plasma spraying (VPS) method. An optimum coating procedure was developed and coating thicknesses of $409{\mu}m$ (without an interlayer) and $378{\mu}m$ (with an interlayer) were obtained with no cracks and no signs of delamination. The mechanical characteristics and microstructure of the tungsten coating layers were investigated using a Vickers hardness tester, FE-SEM, EDS, and XRD. The effect of a titanium interlayer on the properties of the tungsten coating was investigated. It was shown that the titanium interlayer prevented the diffusion of carbon to the tungsten layer, thereby suppressing the formation of tungsten carbide. Vickers hardness data yielded values that were 62.5 ~ 80.46% of those for bulk tungsten, indicating that tungsten coatings on graphite can be utilized as a plasma-facing material. High heat flux tests were performed by using thermal plasma with a maximum flux of $10MW/^2$. Vickers hardness after the heat flux test is performed to see a change in the mechanical properties. The formationof a tungsten carbide and the effect of the titanium interlayer for the diffusion barrier are investigated by using energy dispersion spectroscopy (EDS).

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.171-174
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• 2000

This study uses neon and xenon gas mixture discharges to determine the effects of the neon plasma emission on the characteristics of visible emission from the stimulation of the red, green, blue(RGB) phosphor layers in a surface-type alternate current plasma display panel(AC PDP). With a mixture of less than 2% xenon to neon, it is found that the luminance changes in the visible emission of the phosphor layers are similar to those of the neon plasma emission. In the range of xenon mix ratio from 2 to 5%, the luminance of the red, green, blue(RGB) phosphor layers decreases with a decrease in the neon plasma emission intensity. However, with a mixture of above 5% xenon to neon, the luminance of the red, green, blue(RGB) phosphor layers increases regardless of a decrease in the neon plasma emission intensity. Furthermore, the color purity of the red, green, blue(RGB) phosphor layers improve as the neon plasma emission intensity decreases. Accordingly, it is concluded that the optical properties of the phosphor layers, including color purity and luminance, depend on the neon plasma discharge emission as well as the visible emission from the stimulation of the phosphor layers.

• Corrosion Science and Technology
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• v.19 no.2
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• pp.51-56
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• 2020

The objective of this study was to improve properties of plasma sprayed HAp layer to titanium substrate by introducing an intermediate layer with two different methods. Before applying Zn doped HAp coating on titanium substrate, an intermediate layer was introduced by titanium plasma spray or titanium anodization. Heat treatments were conducted for some samples after titanium intermediate layer was formed. Zn doped HAp top layer was applied by plasma spraying. Three-point bending test and pull-off adhesion test were performed to determine the adhesion of Zn doped HAp coatings to substrates. Long-term credibility of Zn doped HAp plasma sprayed coatings on titanium was assessed by electrochemical impedance measurements in Hanks' solution. It was found that both titanium plasma sprayed and titanium anodized intermediate layer had excellent credibility. Strong adhesion to the titanium substrate was confirmed after 12 weeks of immersion for coating samples with titanium plasma sprayed intermediate layer. Samples with titanium anodized intermediate layer showed good bending strength. However, they showed relatively poor resistance against pulling off. The thickness of titanium anodized intermediate layer can be controlled much more precisely than that of plasma sprayed one, which is important for practical application.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.3
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• pp.157-163
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• 2006

This paper described the process of improving durability performance of the exhaust decoupler by the plasma nitriding. The properties of plasma nitriding treatment of AIS1304 stainless steel were tested using specimens before applying plasma nitriding to a mesh ring. In order to analyses the effect of plasma nitriding treatment on the mechanical properties, SEM(Scanning Electron Microscopes), roughness and hardness tester were used. Based on specimen plasma nitriding, we could find appropriate condition for application to the mesh ring of decoupler. To confirm the improved durability performance, we compared the number of cycles, which reaches to fracture, of the nitrided decoupler and that of the unnitrided decoupler by the bending cyclic test. In this test, the durability and wear resistance of the mesh ring are significantly improved by plasma nitriding treatment.

• Journal of the Korean institute of surface engineering
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• v.34 no.5
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• pp.475-480
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• 2001

Diffusion of Cu into the low-k para-xylene based plasma polymer (pXPP) thin films deposited by plasma-enhanced chemical vapor deposition using the para-xylene precursor was comparatively measured using various methods. Cu layer was deposited on the surfaces of pXPPs treated by $N_2$ plasma generated in a magnetically enhanced inductively coupled plasma reactor. Diffusion characteristics of Cu into pXPPs were measured using Rutherford backscattering spectroscopy (RBS), secondary ion mass spectroscopy (SIMS), cross-sectional transmission electron microscopy (XTEM), and current-voltage (I-V) measurements for the vacuum-annealed Cu/pXPPs for 1 hour at $450^{\circ}C$ and were compared. The results showed a correlation between the I-V measurement and SIMS data are correlated and have a sensitivity enough to evaluate the dielectric properties but the RBS or XTEM measurements are not sufficient to conclude the electrical properties of low-k dielectrics with Cu in the film bulk. The additional results indicate that the pXPP layers are quite resistant to Cu diffusion at the annealing temperature of $450^{\circ}C$ compared to the other previously reported organic low-k materials.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.49.1-49.1
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• 2010

The particle generation during the plasma enhanced process is highly considered as serious problem in the semiconductor manufacturing industry. The material for the plasma processing chamber requires the plasma etching characteristics which are homogeneously etched surface and low plasma etching depth for preventing particulate contamination and high durability. We found that the materials without grain boundaries can prevent the particle generation. Therefore, the amorphous material with the low plasma etching rate may be the best candidate for the plasma processing chamber instead of the polycrystalline materials such as yttria and alumina. Three glasses based on $SiO_2$ and $Al_2O_3$ were prepared with various rare-earth elements (Gd, Y and La) which are same content in the glass. The glasses were plasma etched in the same condition and their plasma etching rate was compared including reference materials such as Si-wafer, quartz, yttria and alumina. The mechanical and thermal properties of the glasses were highly related with cationic field strength (CFS) of the rare-earth elements. We assumed that the plasma etching resistance may highly contributed by the thermal properties of the fluorine byproducts generated during the plasma exposure and it is expected that the Gd containing glass may have the highest plasma etching resistance due to the highest sublimation temperature of $GdF_3$ among three rare-earth elements (Gd, Y and La). However, it is found that the plasma etching results is highly related with the mechanical property of the glasses which indicates the cationic field strength. From the result, we conclude that the glass structure should be analyzed and the plasma etching test should be conducted with different condition in the future to understand the plasma etching behavior of the glasses perfectly.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.1
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• pp.8-12
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• 2005

Indium tin oxide(ITO) surface treated by Oxygen plasma has been in situ analyzed using XPS(X-ray Photoelectron Spectroscopy) and EDS(Energy Dispersive Spectroscopy), to investigate the relations between the properties of the ITO surface and the properties of OLED(Organic Light Emitting Diode). We measured electrical resistivity using Four-Point-Probe and calculated sheet resistance, and ITO surface roughness was measured by AFM(Atomic Force Microscope). We fabricated OLED using substrate that was treated optimum ITO surface. The plasma treatment of the ITO surface lowered the operating voltage of the OLED. We have obtained an improvement of luminance and decrease of turn-on voltage.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1838-1840
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• 1996

In order to study the relationship between the physical properties of glow discharge plasma and the physical behavior of TiN thin film, electrical characteristics of RF discharge plasma driven at 13.56MHz in a parallel-plate electrode system were measured. Plasma parameters, such as electron density and temperature, are also studied since they may be considered as one of the very important factors deciding the physical properties of TiN thin film under given conditions of applied biasd voltage and pressure. The TiN thin film were fabricated over a wide range of discharge conditions, and some of the general relationships between the measured plasma parameters and the properties of TiN thin film were discussed.