• 제목/요약/키워드: Deposition Characteristics

검색결과 2,544건 처리시간 0.031초

기계 부품 재제조를 위한 DED 공정 조건에 따른 적층 및 잔류응력 특성 분석 (Investigation into the Effects of Process Parameters of DED Process on Deposition and Residual Stress Characteristics for Remanufacturing of Mechanical Parts)

  • 김단아;이광규;안동규
    • 소성∙가공
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    • 제30권3호
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    • pp.109-118
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    • 2021
  • Recently, there has been an increased interest in the remanufacturing of mechanical parts using metal additive manufacturing processes in regards to resource recycling and carbon neutrality. DED (directed energy deposition) process can create desired metallic shapes on both even and uneven substrate via line-by-line deposition. Hence, DED process is very useful for the repair, retrofit and remanufacturing of mechanical parts with irregular damages. The objective of the current paper is to investigate the effects DED process parameters, including the effects of power and the scan speed of the laser, on deposition and residual stress characteristics for remanufacturing of mechanical parts using experiments and finite element analyses (FEAs). AISI 1045 is used as the substrate material and the feeding powder. The characteristic dimensions of the bead shape and the heat affected zone (HAZ) for different deposition conditions are obtained from the experimental results. Efficiencies of the heat flux model for different deposition conditions are estimated by the comparison of the results of FEAs with those of experiments in terms of the width and the depth of HAZ. In addition, the influence of the process parameters on residual stress distributions in the vicinity of the deposited region is investigated using the results of FEAs. Finally, a suitable deposition condition is predicted in regards to the bead formation and the residual stress.

LENS 공정을 이용한 Inconel 718 초합금의 S45C 구조용강 위 적층 특성 고찰에 관한 기초 연구 (A Preliminary Study on the Lamination Characteristics of Inconel 718 Superalloy on S45C Structural Steel using LENS Process)

  • 김현식;이협;안동규
    • 한국기계가공학회지
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    • 제20권1호
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    • pp.16-24
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    • 2021
  • A laser-engineered net shaping (LENS) process is a representative directed energy deposition process. Deposition characteristics of the LENS process are greatly dependent on the process parameters. The present paper preliminarily investigates deposition characteristics of Inconel 718 superalloy on S45C structural steel using a LENS process. The influence of process parameters, including the laser power and powder feed rate, on the characteristics of the bead formation and the dilution in the vicinity of the deposited region is examined through repeated experiments. A processing map and feasible deposition conditions are estimated from viewpoints of the aspect ratio, defect formation, and the dilution rate of the deposited bead. Finally, an appropriate deposition condition considering side angle, deposition ratio, and buy-to-fly (BTF) is predicted.

낙동강 하구역의 퇴적특성에 관한 연구 (A Study on the Characteristics of Deposition in Nakdong Estuary)

  • 류승우;김종인;류청로
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2001년도 춘계학술대회 논문집
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    • pp.154-159
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    • 2001
  • Nakdong estuary is located at south-eastern coast of the Korea. A lot of sediment from upper river was deposited at this area. It has caused many problems such as changes in topography and tidal current. In this paper, field observation data on tidal currents and sediments were investigated as well as historical topographic changes by dredging and reclamation of the foreshore. Then, the numerical model considered the settling velocity of the suspended solids according to the particle size was applied to examine the characteristic of deposition. The results are as follows : 1. Changes of characteristics of deposition were caused by topographic changes of Nakdong estuary 2. Characteristics of deposition were influenced by river plume and tidal currents. 3. Numerical model which considers settling velocity reappeared distribution of deposition by particle-size. 4. Used model is only resonable for discussion in the quality, so, it is strongly suggested that the new model development is needed including the quatitative deposition processes.

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AlSi12 분말의 직접 레이저 용융 적층 시 공정 조건에 따른 적층 특성에 관한 연구 (Study on Effects of Direct Laser Melting Process Parameters on Deposition Characteristics of AlSi12 powders)

  • 서자예;윤희석;이기용;심도식
    • 소성∙가공
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    • 제27권5호
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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.

Hot Wall 법의 반복 증착에 의해 제작한 ZnS:Mn 박막 엘렉트로루미네센스의 특성 (Characteristics of Zns:Mn Thin Film Electroluminescences Prepared by a Repeated Deposition of Hot Wall Method)

  • 이상태
    • 한국항해학회지
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    • 제25권4호
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    • pp.435-442
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    • 2001
  • A new technique to grow a manganese-doped zinc-sulfide(ZnS:Mn) has been proposed using the repeated deposition of the Hot Wall method. The optical characteristics and crystallinity for the ZnS and ZnS:Mn thin films deposited on a quartz glass substrate by the method were investigated. Also, The ZnS:Mn thin film elcetroluminescent devices were fabricated by the method to study luminescence characteristics. All films showed (111)-oriented cubic structure. By the repeated deposition, the deposition rates were decreased, and the optical characteristics and crystalline properties were improved, which clarifies that the method is effective to deposit the thin films with good crystallinity Futhermore, the crystallinity was more improved by the doping of Mn. Only one peak emission at around 585nm originating from Mn luminescent center is observed In the photoluminescent and electroluminescent spectra of ZnS:Mn films and the luminance of the ZnS:Mn-based thin film electroluminescent devices was obtained below 60cd/$m^2$ . The optical and crystalline properties, luminescence characteristics are discussed in terms of the effects of the repeated deposition and Mn-doping.

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DC Magnetron Sputtering에 의한 ATO 박막의 제조 (I)증착특성 (Preparation of ATO Thin Films by DC Magnetron Sputtering (I) Deposition Characteristics)

  • 윤천;이혜용;정윤중
    • 한국세라믹학회지
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    • 제33권4호
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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.

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실리콘질화막의 기상성장과 그 전기적 특성 (Vapor deposition of silicon nitride film on silicon and its electrical properties)

  • 성영권;민남기;김승배
    • 전기의세계
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    • 제28권9호
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    • pp.43-50
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    • 1979
  • Silicon nitride films were chemically deposited on silicon substrates by reacting SiCl$_{4}$ and NH$_{3}$ in a nitrogen atmosphere at 700~1100 .deg.C. The deposition rate increased rapidly with deposition temperature upto about 1000 .deg.C, and became less temperature dependent above this temperature. The etch rate of films in buffered HF solution decreased, with an increase of deposition temperature, and a heat treatment at a temperature higher than that of the deposition considerably reduced the etch rate. It indicates that the heat treatment resulted in a densification of the films. Surface charge density of 3~4 * 10$^{11}$ /cm$^{2}$ was determined from the C-V characteristics of MNS diode, and it was also found that surface charge density depended on deposition temperature, but not film thickness. The current-voltage characteristics displayed a logI-V$^{1}$2/ dependence in the temperature range of 300~500.deg.K. Measurement of the slope of this characteristics and its dependence on temperature and bias polarity suggest that conduction in sili con nitride films arises from the Poole-Frenkel mechanism.

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유기발광 다이오드의 물성에 미치는 증착속도의 영향 (The Effects of Deposition Rate on the Physical Characteristics of OLEDs)

  • 이영환;차기호;김원종;이종용;김귀열;홍진웅
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 학술대회 및 기술세미나 논문집 디스플레이 광소자
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    • pp.54-55
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    • 2006
  • Organic light-emitting diodes(OLEOs) are attractive because of possible application in display with low operating voltage, low power consumption, self-emission and capability of multicolor emission by the selection of emissive material. We investigated the effects of deposition rate on the electrical characteristics, physical characteristics and optical characteristics of OLEOs in the ITO(indium-tin-oxide)/N.N'-diphenyl-N,N'-bis(3-methyphenyl)-1,1'-biphenyl-4,4'-diamine(TPD)/tris(8-hydroxyquinoline)aluminum($Alq_3$)/Al device. We measured current density, luminous flux and luminance characteristics of devices with varying deposition rates of TPD and $Alq_3$. It has been found that optimal deposition rate of TPD and $Alq_3$ were respectively $1.5{\AA}/s$ from the device structure. An AFM measurement results, surface roughness of the deposited film was the lowest when deposition rate was $1.5{\AA}/s$.

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정전효과를 고려한 반도체 웨이퍼의 입자침착 특성 (Particle Deposition Characteristics with Electrostatic Effect on Semiconductor Wafers)

  • 이건형;채승기;문영준
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.779-785
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    • 2006
  • Particle transport and deposition characteristics on semiconductor wafers inside the chamber were experimentally investigated via a particle generation & deposition system and a wafer surface scanner. Especially the relation between particle size($0.083{\sim}0.495{\mu}m$) and particle deposition velocity with ESA(Electrostatic Attraction) effect was studied. Spot deposition technique with the deposition system using nozzle type outlets of the chamber was newly conducted to derive particle deposition velocity and all experiment results were compared with the previous study and were in a good agreement as well.

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Characteristics of Hafnium Silicate Films Deposited on Si by Atomic Layer Deposition Process

  • Lee, Jung-Chan;Kim, Kwang-Sook;Jeong, Seok-Won;Roh, Yong-Han
    • Transactions on Electrical and Electronic Materials
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    • 제12권3호
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    • pp.127-130
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    • 2011
  • We investigated the effects of $O_2$ annealing (i.e., temperature and time) on the characteristics of hafnium silicate ($HfSi_xO_y$) films deposited on a Si substrate by atomic layer deposition process (ALD). We found that the post deposition annealing under oxidizing ambient causes the oxidation of residual Hf metal components, resulting in the improvement of electrical characteristics (e.g., hysteresis window and leakage current are decreased). In addition, we observed the annealing temperature is more important than the annealing time for post deposition annealing. Based on these observations, we suggest that post deposition annealing under oxidizing ambient is necessary to improve the electrical characteristics of $HfSi_xO_y$ films deposited by ALD. However, the annealing temperature has to be carefully controlled to minimize the regrowth of interfacial oxide, which degrades the value of equivalent oxide thickness.