• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.900-903
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• 2003

Using $DV-X{\alpha}$ method, it is calculated that nickel reduces the energy band gap of manganese oxide in 3 additives of titanium, nickel and tin. Therefore, it is estimated that the electrical conductivity of manganese-nickel oxide has the lowest value in 3 kinds of manganese oxide. The manganese oxide and manganese-nickel oxide which were produced by anodic deposition under $30mA/cm^2$ at room temperature in manganese sulfate and manganese-nickel sulfate solution were thermal-analyzed by DTA and TGA. The weight change of manganese oxide continuously decreased below $508^{\circ}C$ and kept constant at $518{\sim}600^{\circ}C$. However, the manganeses-nickel oxide transformed at the temperature range of $510{\sim}537^{\circ}C$. It is observed that the nickel addition to manganese oxide increases transformation temperature and its range.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.347-350
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• 2001

A typical Mold method is to form a gate electrode, a gate oxide, and emitter tip after fabrication of mold shape using wet-etching of Si substrate. In this study, however, new Mold method using a side wall space structure is used in order to make sharper emitter tip with a gate electrode. Using LPCVD(low pressure chemical vapor deposition), a gate oxide and electrode layer are formed on a Si substrate, and then BPSG(Boro phospher silicate glass) thin film is deposited. After, the BPSG thin film is flowed into a mold as high temperature in order to form a sharp mold structure. Next TiN thin film is deposited as a emitter tip substance. The unfinished device with a glass substrate is bonded by anodic bonding techniques to transfer the emitters to a glass substrate, and Si substrate is etched using KOH-deionized water solution. Finally, we made sharp field emitter array with gate electrode on the glass substrate.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.593-596
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• 2007

A possibility of manufacturing bendable ac-PDP using aluminum electrode with anodic aluminum oxide dielectric material system on PET film substrate was explored. For this structure, PET film with fence-structured aluminum electrodes was used for front plate and PET film with barrier ribs of UV curable resin for the rear plate. The results demonstrate that it is feasible to manufacture the bendable ac-PDPs using those material system and are expected to expand the applications of plasma display panels.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.557-558
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• 2006

The mechanical properties of micro-hardness and internal stress of Ni-Fe alloy thin film made by electrodeposition method have been measured as a function of bath composition and current density. And also the microstructure of $200{\AA}$ Ni-Fi nanowires made using anodic aluminum oxide(AAO) templates by electrodeposition method have been observed by SEM as a function of ultrasonic treatment time and bath composition.

• Corrosion Science and Technology
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• v.14 no.3
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• pp.140-146
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• 2015

The commercialization of aluminum had been delayed than other metals because of its high oxygen affinity. Anodizing is a process in which oxide film is formed on the surface of a valve metal in an electrolyte solution by anodic oxidation reaction. Aluminum has thin oxide film on surface but the oxide film is inhomogeneous having a thickness only in the range of several nanometers. Anodizing process increases the thickness of the oxide film significantly. In this study, porous type oxide film was produced on the surface of aluminum in sulfuric acid as a function of electrolyte temperature, and the optimum condition were determined for anodizing film to exhibit excellent cavitation resistance in seawater environment. The result revealed that the oxide film formed at $10^{\circ}C$ represented the highest cavitation resistance, while the oxide film formed at $15^{\circ}C$ showed the lowest resistance to cavitation in spite of its high hardness.

• Tribology and Lubricants
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• v.27 no.4
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• pp.193-197
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• 2011

Friction behavior of nanoporous anodic aluminum oxide(AAO) film was investigated. A 60 ${\mu}m$ thick AAO film having nanopores of 45 nm diameter with 105 nm interpore-diatance was fabricated by mild anodization process. The AAO film was then saturated with paraffinic oil. Reciprocating ball-on-flat sliding friction tests using 1 mm diameter steel ball as the counterpart were carried out with normal load ranging from 0.1 N to 1 N in an ambient environment. The morphology of worn surfaces were analyzed using scanning electron microscopy. The friction coefficient significantly increased with the increase of load. The boundary lubrication layer of paraffinic oil contributed to the lower friction at relatively low load (0.1 N), but it is less effective at high load (1 N). Plastic deformed layer patches were formed on the worn surface of oil-enriched AAO at relatively low load (0.1 N) without evidence of tribochemical reaction. On the other hand, thick tribolayers were formed on the worn surface of both oil-enriched and as-prepared AAO at relatively high load (1 N) due to tribochemical reaction and material transfer.

• Korean Journal of Materials Research
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• v.26 no.3
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• pp.160-165
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• 2016

To increase the capacitance of an Al electrolytic capacitor, the anodic oxide film, $Al_2O_3$, was partly replaced by an $Al_2O_3-ZrO_2$ (Al-Zr) composite film prepared by the vacuum infiltration method and anodization. The microstructure and composition of the prepared samples were investigated by scanning electron microscopy and transmission electron microscopy. The coated and anodized samples showed multi-layer structures, which consisted of an inner Al hydrate layer, a middle Al-Zr composite layer, and an outer $Al_2O_3$ layer. The thickness of the coating layer could go up to 220 nm when the etched Al foil was coated 8 times. The electrical properties of the samples, such as specific capacitance, leakage current, and withstanding voltages, were also characterized after anodization at 100 V and 600 V. The capacitances of samples with $ZrO_2$ coating were 36.3% and 27.5% higher than those of samples without $ZrO_2$ coating when anodized at 100 V and 600 V, respectively.

• Journal of the Korean institute of surface engineering
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• v.51 no.6
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• pp.381-386
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• 2018

In this study, plasma electrolytic oxidation (PEO) method was used to from anodic oxide films on Al alloy and their resistance and morphological characteristics were investigated as a function of film formation voltage and treatment time. Cross-sectional morphology and composition of the PEO films were analyzed by SEM (Scanning Electron Microscopy) and EDS (Energy Dispersive Spectroscopy). The PEO films showed increased surface roughness and thickness with of film formation voltage and treatment time. The wear resistance was found to be the best for the PEO film formed for 5 min at 500V which is attributed to be denser structure relatively and lower surface roughness.

• Journal of Electrochemical Science and Technology
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• v.3 no.4
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• pp.185-189
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• 2012

A.c. impedances of mechanically polished CP-Ti specimens were measured at open-circuit potential (OCP) with immersion time and under applied anodic potentials between -0.2 and 1 $V_{Ag/AgCl}$ in 0.1 M NaOH solution. Capacitances of native oxide films ($C_{ox,na}$) grown naturally and capacitances of anodic oxide films ($C_{ox,an}$) formed under applied anodic potentials were obtained to examine the growth of native and anodic oxide films in 0.1 M NaOH solution and how to use $C_{ox,na}$ for the surface area measurement of Ti specimen. $1/C_{ox,na}$ and $1/C_{ox,an}$ appeared to be linearly proportional to OCP and applied potential ($E_{app}$), with proportional constants of 0.086 and 0.051 $uF^{-1}\;V^{-1}$, respectively. The $C_{ox,na}$ also appeared to be linearly proportional to geometric surface area of the mechanically polished CP-Ti fixture specimen, with proportional constants of 11.3 and $8.5{\mu}F\;cm^{-2}$ at -0.45 $V_{Ag/AgCl}$ and -0.25 $V_{Ag/AgCl}$ of OCPs, respectively, in 0.1 M NaOH solution. This linear relationship between $C_{ox,na}$ and surface area is suggested to be applicable for the measurement of real surface area of Ti specimen.

• Journal of the Korean institute of surface engineering
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• v.48 no.4
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• pp.142-148
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• 2015

The effect of equal channel angular pressing (ECAP) on the pitting corrosion resistance of hard anodized Al5052 alloy was investigated. The degree of internal stress generated in anodic oxide films during hard anodization was also evaluated with a strain gauge method. The pitting corrosion resistance of hard anodized Al5052 alloy was greatly decreased by ECAP. Cracks occurred in the anodic oxide film during hard anodization and these cracks were larger and deeper in the alloy with ECAP than without. The pitting corrosion was accelerated by cracks. The internal stress present in the anodic oxide films was compressive and the stress was higher in the alloys with ECAP than without, resulting in an increased likelihood of cracks. The pitting corrosion resistance of hard anodized Al5052 alloy was improved by annealing at the range of 473-573K after ECAP processed at room temperature for four passes. The compressive internal stress gradually decreased with increasing annealing temperature. It is assumed that the improvement in the pitting corrosion resistance of hard anodized Al5052 alloy by annealing may be attributed to a decrease in the likelihood of cracks due to the decreased internal stresses in anodic oxide films.