• Applied Chemistry for Engineering
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• 제29권2호
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• pp.196-200
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• 2018

In this study, the intermediate layer in Pd-based hydrogen separation membrane was synthesized to minimize the surface roughness and defects using powder-type and sol-type metal oxides. The surface properties and gas permeation characteristics were analysed by SEM and $N_2$ gas permeation test. The coating layer composed of sol type metal oxides has smooth surface, especially the layer coated by $TiO_2$ sol has little pin holes, cracks and defects. The binary layer composed of powder type and sol type metal oxides has similar flux characteristics to a single sol type layer. The Pd-based composite membrane improved by the binary intermediate layer exhibited $0.32mol/m^2s$ of the hydrogen permeation flux with a selectivity ($H_2/N_2$) of ~10,890 at 672 K and a pressure difference of 1 bar.

• Journal of Mechanical Science and Technology
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• 제17권12호
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• pp.1904-1911
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• 2003

In order to determine the wear properties of AIP (Arc Ion Plating) deposition, wear process was evaluated by using a Falex test machine. Also, in order to determine the effects of coating material on the wear process, TiC, TiN, and TiCN coatings of thickness about 5 $\mu\textrm{m}$∼6 $\mu\textrm{m}$ coated by Arc ion plating deposition method were tested. The wear property was determined under a dry sliding condition as a function of the applied load, sliding distance, sliding velocity and temperature. The results show that when wear of the coating-layer occurred, specific wear amount increased with the wear rate. At initial state, the wear rate rapidly increased, but it gradually reduced as the velocity increased. Also, when raising the temperature, the wear rate increased in the order of TiCN, TiN and TiC due to the frictional heat.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제58권11호
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• pp.2214-2218
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• 2009

Dye-sensitized solar cell (DSC) has been considered as a possible alternative to current silicon based p-n junction photovoltaic devices due to its advantages of high efficiency, simple fabrication process and low production cost. Numerous researches for high efficient DSC in the various fields are under way even now. Among them, the compact layer, which prevents the back electron transfer between transparent conductive oxides and the redox electrolyte, is fabricated by various methods such as a ZnO dip-coating, $TiCl_4$ dip-coating, and Ti sputtering. In this study, we tried to fabricate the $TiO_2$ compact layer by the spin-coating method using aqueous $TiCl_4$ solution. The effect of the spin-coating method was checked as compared with conventional dip-coating method. As a result, DSC with a spin-coated compact layer had 33.4% and 6% better efficiency than standard DSC and DSC with a dip-coated compact layer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.288-291
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• 2002

Application of metal silicides such as TiSi$_2$ and CoSi$_2$ as contacts and gate electrodes are being studied. However, TiSi$_2$ due to the linewidth-dependance, and CoSi$_2$ due to the excessive Si consumption during silicidation cannot be applied to the deep-submicron MOSFET device. NiSi shows no such problems and can be formed at the low temperature. But, NiSi shows thermal instability. In this investigation, NiSi was formed with a Ti-capping layer to improve the thermal stability. Ni and Ti films were deposited by the thermal evaporator. The samples were then annealed in the N$_2$ ambient at 300-800$^{\circ}C$ in a RTA (rapid thermal annealing) system. Four point probe, FESEM, and AES were used to study the thermal properties of Ti-capped NiSi layers. The Ti-capped NiSi was stable up to 700$^{\circ}C$ for 100 sec. RTA, while the uncapped NiSi layers showed high sheet resistance after 600$^{\circ}C$. The AES results revealed that the Ni diffusion further into the Si substrate was retarded by the capping layer, resulting in the suppression of agglomeration of NiSi films.

• Transactions of Materials Processing
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• 제31권4호
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• pp.179-185
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• 2022

The influence of post-roll bonding heat treatment conditions such as temperature and time on the variation in the diffusion layer, generated at the bonding interface and the subsequent mechanical properties of the roll-bonded Ti grade 1/Al1050/Ti grade 1 sheets, was systematically investigated. The intermetallic compound (IMC) phase generated by post heat treatment conditions adopted in this study was obviously indexed as monolithic TiAl₃. Whereas the thickness of IMC layer generated by annealing at 500 ℃ was approximately 100 nm scale, it drastically increased above 1.5 ㎛ when annealed at 600 ℃. Uniaxial tensile and peel tests were then performed to compare mechanical properties. As a result, the bonding strength drastically increased above 7.9 N/mm by annealing at 600 ℃, which implies that proper annealing condition was a prerequisite, to improving interface bonding strength as well as global elongation properties for Ti/Al/Ti 3-ply sheet.

• Journal of Surface Science and Engineering
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• 제28권6호
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• pp.368-375
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• 1995

Thermal CVD method is in general used for the fabrication of TiC/$Al_2O_3$-coated carbide tools. The growth of TiC layer and the coating morphology depended on the chemical composition of the hard metal substrate on which the tool properties were strongly influenced. TiC-coated layer was grown by the diffusion of carbon from the substrate, whereas the growth of $Al_2O_3$ layer was unrelated to the composition of substrate. In the nitride hard coatings of Zr, Nb and Mo metals deposited on high speed steel substrate by magnetron sputtering, the reactivity of the metal elements was decreased with increasing group number in one period of the periodic system. The hard material films exhibited the highest adhesion with the chemical composition of stoichiometry or substoichiometry. The critical load as a measure of adhesion was evaluated using scratch tester. The CVD tools indicated the values of 80 and 40N in the coated layers with proper bonding to the substrate and with $\eta$ phase of 1$\mu\textrm{m}$ in the interface respectively, but the nitride films prepared by sputtering of PVD showed only the values between 10 and 20N.

• Journal of Power System Engineering
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• 제9권1호
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• pp.76-81
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• 2005

The effect of micro-pulse plasma nitriding temperature and time on the case thickness, hardness and nitride formation in the surface of Fe-12Cr-22Mn-X alloy with 3% Co and 1% Ti alloys elements investigated. External compound layer and internal diffusion layer was constituted in plasma nitride case of Fe-12Cr-22Mn-X alloys and formed nitride phase such as ${\gamma}'-Fe4N\;and\;{\varepsilon}-Fe2-3N$. Case depth increased with increasing the plasma nitriding temperature and time. Surface hardness of nitrided Fe-12Cr-22Mn-X alloys obtained the above value of Hv 1,600 and case depth obtained the above value of $45{\mu}m$ in Fe-12Cr-22Mn-3Co alloy and $60{\mu}m$ in Fe-12Cr-22Mn-1Ti alloy. Wear-resistance increased with increasing plasma nitriding time and showing the higher value in Fe-12Cr-22Mn-1Ti alloy than Fe-12Cr-22Mn-3Co alloy.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제26권2호
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• pp.67-73
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• 2016

The degradation behaviors of TiN coating layers under thermo-mechanical stress were investigated in terms of comparison of finite element analysis (FEA) and experimental data. The coating specimen was designed to quarter cylinder model, and the pulsed laser ablation was assumed as heat flux condition. The FEA results showed that heat accumulation at the center of the laser-ablated spot occurred and principle stress was concentrated at the lower region of the coating layer. The microstructural observation revealed that surface melting and decrease of the coating thickness occurred in the TiN/Inconel 617 and the interfacial cracks formed in the TiN/Si. The delamination was caused by the mechanical stress from the center to the outside of the ablated spot as the FEA results expected. It was considered that the improvement of the thermal shock resistance was attributed to higher thermal conductivity of Si wafer than that of Inconel 617.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제3권2호
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• pp.115-119
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• 2002

This study was performed to improve mechanical properties of rotor and bushing materials. SACD and SKD11 steels as rotor and bushing materials were investigated. Gas nitriding and TiN coating were carried out on SACM and SKD11 steels. TiN coating was deposited on SKD11 steel by reactive sputtering process. This coated layer was picked off during the operation because of insufficient adhesion. Gas nitriding was carried out on SACM and SKD11 steels in an ammonia atmosphere at 51$0^{\circ}C$ for 72 hrs. These gas nitrided parts showed good mechanical properties. SKD11 steels were heat-treated to obtain optimum carbide size and distribution. As a results, the hardness increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.118-119
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• 2005

PRAM (Phase Change Random Access Memory) is well known to use reversible phase transition between amorphous (high resistance) and crystalline (low resistance) states of chalcogenide thin film by electrical Joule heating. In this paper, we introduce a stack-type PRAM device with a novel GST/TiAlN structures (GST and a heating layer of TiAlN), and report its electrical switching properties. XRD analysis result of GST thin film indicates that the crystallization of the GST film start at about $200^{\circ}C$. Electrical property results such as I-V & R-V show that the phase change switching operation between set and reset states is observed, as various input electrical sources are applied.