• Corrosion Science and Technology
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• v.18 no.6
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• pp.228-231
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• 2019

Aluminum and its alloys have been widely used in various fields because of low weight, high strength, good conductivity, and low price. It is well known that aluminum alloys that cause natural oxide film can inhibit corrosion in wet, salty environments. However, these oxides are so thin that corrosion occurs in a variety of environments. To prevent this problem, an electrochemical anodizing technique was applied to the aluminum alloy surface to form a thick layer of oxide and a unique oxide shape, such as a hierarchical pore structure simultaneously combining large and small pores. The shape of the structures was implemented using stepwise anodization voltages such as 40 V for mild anodizing and 80 V for hard anodizing, respectively. To maximize water repellency, it is crucial to the role of surface structures shape. And a hydrophobic thin film was coated by 1H, 1H, 2H, 2H-Perfluorodecyltrichlorosilane (FDTS) to minimize surface energy of the structure surface. Thus, such nanoengineered superhydrophobic surface exhibited a high water contact angle and excellent corrosion resistance such as low corrosion current density and inhibition efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.407-408
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• 2005

High surface area electrodes for aluminum electrolytic capacitors are produced by AC electrochemical processes. Optimization of crystallographic etch pit growth on aluminium during AC etching of cathode film for aluminium as electrolytic capacitor has been established. In this work, we present the observations of pit distributions by galvanostatic measurements. The effects of electrolyte concentration, current density, frequency, various pre-treatments and etching time have been studied. The specimen was pretreated in 0.5M NaOH and 1M HCl at $40\sim60^{\circ}C$, and transferred into a cell containing 1M HCl, then various mol $H_2SO_4$ etchant was added. Pit size distributions were determined with scanning electron microscopy (SEM).

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.96.2-96.2
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• 2010

The surface morphology and structural properties of polycrystalline silicon (poly-Si) films made in-situ aluminum induced crystallization at various substrate temperature (300~600) was investigated. Silicon films were deposited by hot-wire chemical vapor deposition (HWCVD), as the catalytic or pyrolytic decomposition of precursor gases SiH4 occurs only on the surface of the heated wire. Aluminum films were deposited by DC magnetron sputtering at room temperature. continuous poly-Si films were achieved at low temperature. from cross-section TEM analyses, It was confirmed that poly-Si above $450^{\circ}C$ was successfully grown on and poly-Si films had (111) preferred orientation. As substrate temperature increases, Si(111)/Si(220) ratio was decreased. The electrical properties of poly-Si film were investigated by Hall effect measurement. Poly-Si film was p-type by Al and resistivity and hall effect mobility was affected by substrate temperature.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.207-211
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• 2002

Anodizing film was prepared by anodic oxidation of pure aluminum(purity > 99.50) using DC power supply for constant current mode in an electrolytic solution of surface of sulfuric acid. Effects of pre-treatment process such as chemical polishing, acid cleaning, alkali etching before anodic oxidation, were studied to microstructures and surface morphologies. A roughness on surface of anodizing film had to be decreased for amorphous phase by anodic oxidation. A roughness on surface of anodizing film decrease as annealing temperature increased in chemical polishing.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.29-32
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• 2000

Meta1-ferroelectric-insulator-semiconductor(MFIS) devices using Pt/LiNbO$_{3}$/AIN/Si structure were successfully fabricated. AIN thin films were made into metal-insulator-semiconductor(MIS) devices by evaporating aluminum in a dot array on the film surface. The dielectric constant of the AIN film calculated from the capacitance in the accumulation region in the capacitance-voltage(C-V ) characteristic is 8. The gate leakage current density of MIS devices using a aluminum electrode showed the least value of 1$\times$10$^{-8A}$ $\textrm{cm}^2$ order at the electric field of 500㎸/cm. A typica] value of the dielectric constant of MFIS device was about 23 derived from 1MHz capacitance-voltage (C-V) measurement and the resistivity of the film at the field of 500㎸/cm was about 5.6$\times$ 10$^{13}$ $\Omega$.cmcm

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2521-2523
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• 1998

Freestanding flexible microstructures fabricated from deposited thin films become mechanically unstable when internal stresses exceed critical values. The residual stress and stress gradient of aluminum thin film were examined to make sure of fabricating the reproduceable aluminium structure. For good shape of micro mirror array and microstructures, the experiment was done varying thickness and deposition rate. As the aluminium film thickness increased from 0.8${\mu}m$ to 1.6${\mu}m$, the stress gradient decreased from 11.62MPa/${\mu}m$ to 2.62MPa/${\mu}m$. The residual stress values are from 42.4MPa to 62.24MPa of tensile stresses.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.265-269
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• 1989

Effects of air-tighteness of packing material and aluminum phosphide fumigation on mortality of rice weevil were studied during rice storage. Air-tight storage of rice in sealed bag of 0.1mm PE film or sealed glass bottle reduced the deterioration of rice quality and killed all rice weevils after 60 days storage, while paper bag, PP bag and straw bag storage kept them alive. One tablet of aluminum phosphide in one cubic meter heap of rice packed in PP bag was sufficient to kill all rice weevil in it, when the heap was covered by 0.15 mm PE film during fumigation.

• 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.

• Transactions on Electrical and Electronic Materials
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• v.12 no.6
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• pp.267-270
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• 2011

In the process of inkjet-printed zinc tin oxide thin-film transistor, the effect of metallic interlayer underneath of source and drain electrode was investigated. The reason for the improved electrical properties with thin molybdenum oxide ($MoO_3$) layer was due to the chemically intermixed state of metallic interlayer, aluminum source and drain, and oxide semiconductor together. The atomic configuration of three Mo $3d_3$ and $3d_5$ doublets, three different Al 2p core levels, two Sn $3d_5$, and four different types of oxygen O 1s in the interfaces among those layers was confirmed by X-ray photospectroscopy.

• 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.