• Journal of the Korean Ceramic Society
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• v.37 no.2
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• pp.194-200
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• 2000

Sb-doped tin oxide films were deposited on Corning glass 1737 substrate by plasma enhanced chemical vapor deposition(PECVD) technique using a gas mixture of SnCl4/SbCl5/O2/Ar. The deposition behaviors of tin oxide films by PECVD were compared with those by thermal CVD, and effects of deposition temperature, r.f. power and Sb doping on the electrical properties of tin oxide films were investigated. PECVD technique largely increased the deposition rate and smoothed the surface of tin oxide films compared with thermal CVD. Electrical resistivity decreased with doping of Sb due to the increase of carrier concentration. However, large doping of Sb diminished carrier concentration and mobility due to the decrease of crystallinity, which resulted in the increase of electrical resistivity. As the deposition temperature and r.f. power increased, Cl content in the film decreased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.21-24
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• 2000

Properties of thermoelectric power in PbS thin films by chemical bath deposition were investigated The qualified PbS thin film was gained with the amounts of Thiourea($4-8ml/{\ell}$ ), Triethanolamine (1-2ml) and NaOH(l0ml). The molecular ratio of Pb and S was 3 : 7. Satisfied crystallization rate and deposition rate of PbS were greater at $50^{\circ}C$ than at $30^{\circ}C$. The constant of thermoelectric power in PbS was nearly $ 500uv/^{\circ}k$. The PbS thin film was changed from p-type to n-type semiconductor at around $200^{\circ}C$. In case of heat treatment at $300^{\circ}C$, the sample kept the characteristic of p-type semiconductors up to $250^{\circ}C$.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.180-180
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• 2010

The design and implementation of high rate deposition process and anti-scratch property of silicon oxide film by PECVD with UHF power were investigated according to the effect of UHF input power with HF bias. New regime of high rate deposition of SiOx films by hybrid plasma process was investigated. The dissociation of OMCTS (C8H24Si4O4) precursor was controlled by plasma processes. SiOx films were deposited on polyethylene terephthalate (PET) and polycarbonate substrate by plasma enhanced chemical vapor deposition (PECVD) using OMCTS with oxygen carrier gas. As the input energy increased, the deposition rate of SiOx film increased. The plasma diagnostics were performed by optical emission spectrometry. The deposition rate was characterized by alpha-step. The mechanical properties of the coatings were examined by nano-indenter and pencil hardness, respectively. The deposition rate of the SiOx films could be controlled by the appropriate intensity of excited neutrals, ionized atoms and UHF input power with HF bias at room temperature, as well as the dissociation of OMCTS.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.4_2
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• pp.699-706
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• 2022

In this study, Directed energy deposition (DED) among additive manufacturing is applied to repair damaged spindle key parts of planner miller. The material of the spindle key is SCM415, and the P21 Powder is used. In order to find the optimal deposition conditions for DED equipment, a single-line deposition experiment is conducted to analysis five parameters. The laser power affects the width, and the height is a parameter affected by coaxial gas and powder gas. In addition, laser power, powder feed rate, coaxial gas, and powder gas are parameters that affect dilution. Otimal deposition is that 400 W of laser power, 4.0 g/min of powder feed rate, 6.5 L/min of coaxial gas, 3.0 L/min of powder gas and 4.5 L/min of shield gas. By setting the optimum conditions, a uniform deposition cross section in the form of an ellipse can be obtained. Damage recovery process of spindle key consists of 3D shape design of the base and deposition parts, deposition path creation and deposition process, and post-processing. The hardness of deposited area with P21 powder on the SCM415 spindle key is 336 HV for the surface of the deposition, 260 HV for the boundary area, and 165 HV for the base material.

• Transactions of Materials Processing
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• v.27 no.5
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• pp.314-322
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• 2018

AlSi12 is a heat-resistant aluminum alloy that is lightweight, corrosion-resistant, machinable and attracting attention as a functional material in aerospace and automotive industries. For that reason, AlSi12 powder has been used for high performance parts through 3D printing technology. The purpose of this study is to observe deposition characteristics of AlSi12 powder in a direct energy deposition (DED) process (one of the metal 3D printing technologies). In this study, deposition characteristics were investigated according to various process parameters such as laser power, powder feed rate, scan speed, and slicing layer thickness. In the single track deposition experiment, an irregular bead shape and balling or humping of molten metal were formed below a laser power of 1,000 W, and the good-shaped bead was obtained at 1.0 g/min powder feed rate. Similar results were observed in multi-layer deposition. Observation of deposited height after multi-layer deposition revealed that over-deposition occurred at all conditions. To prevent over-deposition, slicing layer thickness was experimentally determined at given conditions. From these results, this study presented practical conditions for good surface quality and accurate geometry of deposits.

• Korean Journal of Materials Research
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• v.12 no.1
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• pp.82-88
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• 2002

Chromium carbide films were deposited on high speed steels using a Cr_3C_2$ target by magnetron sputtering. Effects of the deposition parameters (power, Ar pressure and substrate temperature) on deposition rates and surface roughnesses of the films were investigated. The morphologies of those films were characterized by scanning electron microscopy and atomic force microscopy. The grain size of the samples deposited using dc-power is larger than that using equivalent rf-power. The hardness of the sample increases with increasing rf-power, whereas the elastic modulus nearly does not change with rf-power. The optimum sputter deposition conditions for chromium carbide on high speed steels in the corrosion resistance aspect were found to be the rf-power with small roughness.

• Journal of the Korean Ceramic Society
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• v.33 no.4
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• pp.441-447
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• 1996

Sb doped SnO2(ATO:Antinomy doped Tin Oxide) thin films were prepared by a DC magnetron spttuering method using oxide target and the deposition characteristics were investigated. The experimental conditions are as follows :Ar flow rate : 100 sccm oxygen flow rates ; 0-100 sccm deposition temperature ; 250 -40$0^{\circ}C$ DC sputter powder ; 150~550 W and sputtering pressure ; ; 2~7 mTorr. Deposition rate greatly depends not on the deposition temperature but on the reaction pressure oxygen flow rate and sputter power,. when the sputter powder is low ATO thin films with (110) preferred orientation are deposited. And when the sputter power is high (110) prefered orientation appeares with decreasing of oxygen flow rate and increasing of suputte-ring pressure.

• Journal of the Korean Ceramic Society
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• v.30 no.2
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• pp.148-156
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• 1993

TiN films were deposited onto high speed steel (SKH9) by plasma assisted chemical vapor deposition (PACVD) using a TiCl4/N2/H2/Ar gas mixture at around 50$0^{\circ}C$. The effects of the deposition temperature, R.F. power and TiCl4 concentration on the deposition of TiN and the microhardness of TiN film were investigated. The crystallinity and the microhardness of TiN films were improved with increase of the deposition temperature. Optimum deposition temperature in this study was 50$0^{\circ}C$, because a softening or phase transformation of the substrate occurred over 50$0^{\circ}C$. A large increase of the film growth rate with a strong(200) preferred orientation was obtained by increasing R.F. power. Much chlorine content of about 10at.% was found in the deposited films and resulted in relatively low average microhardness of about 1, 500Kgf/$\textrm{mm}^2$ compared with the theoretical value(~2, 000Kgf/$\textrm{mm}^2$).

• Journal of the Korean institute of surface engineering
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• v.38 no.2
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• pp.60-64
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• 2005

The ICP-CVD (inductively coupled plasma chemical vapor deposition) process was applied to the deposition of $TiB_2$ films. For plasma generation, 13.56 MHz r.f. power was supplied to 2-turn Cu coil placed inside chamber. And the gas mixture of $TiCl_4,\;BCl_3,\;H_2$ and Ar was used for $TiB_2$ deposition. $TiB_2$ films with high hardness (<40 GPa) were obtained at extremely low deposition temperature $(250^{\circ}C)$, and the films hardness increased with ICP power and gas flow ratio of $TiCl_4/BCl_3$. The film structure was changed from (100) preferred orientation to random orientation with increasing RF power. It is supposed that the enhanced hardness of films was caused by a strong Ti-B chemical bonding of stoichiometric $TiB_2$ films and film densification induced by high density plasma.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.327-330
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• 2004

Laser aided direct metal deposition (LADMD) process offers the ability to make a metal component directly from 3-D CAD dimensions. A 3-D object can be formed by repeating laser cladding layer by layer. The key of the build-up mechanism is the effective control of powder delivery and laser power to be irradiated into the melt-pool. A feedback control system using optical sensors is introduced to control laser power and powder mass flow rate. Using H13 tool steel and $CO_2$ laser system, comprehensive analysis are executed to test the efficiency of the system. In addition, the dimensional characteristics of directed deposited material are investigated with the parameters of deposition thickness, laser power, traverse speed and powder mass flow rate.