• 제목/요약/키워드: Vacuum Heat Treatment

검색결과 345건 처리시간 0.033초

열처리에 의한 도재용 Ni-Cr합금 표면의 변화에 관한 연구 (METAL SURFACE CHANGES BY HEAT TREATMENT OF Ni-Cr ALLOYS)

  • 김영한;이선형;양재호;정헌영
    • 대한치과보철학회지
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    • 제27권2호
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    • pp.219-248
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    • 1989
  • The purposes of this study were to analyze the microstructural and compositional changes of metal surfaces following different conditions of preoxidizing heat treatment, to investigate the composition of metal oxides, and to evaluate the effect of preoxidation and removal of surface oxides on microstructure and diffusion profiles. The techniques of EDAX (energy-dispersive analysis of x-ray), ESCA (electron spectroscopy for chemical analysis), and EPMA (electron probe micro analysis) were used, along with SEM (scanning electron microscopy). The obtained results were as follows : 1. A surface of the specimen became rough and the amount of the metal oxides increased with increasing the heat treatment time and temperature and the partial pressure of oxygen. 2. At an air pressure of 28' vacuum, the higher the temperature and the longer the time of preoxidation, the higher Ni concentration was detected. 3. Cr concentration in the specimen heat treated with air was higher than that of with vacuum. 4. The oxides in the specimens were mainly composed of Ni and Cr oxides. On the globular growth particles, significant rises in Al concentration of Rexillium III and Ti concentration of Verabond were noted. 5. Atomic diffusion occurred at the ceramic-metal interface, furthermore the amount of the flux was increased with preoxidation heat treatment.

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핵연료 피복관용 지르칼로이-4의 미세조직과 기계적 특성에 미치는 $\beta$-열처리의 영향 (The Effect of $\beta$-Heat Treatment on the Microstructure and Mechanical Characteristics of Zircaloy-4 for Nuclear Fuel Cladding)

  • 고진현;오영근;김광수
    • 한국재료학회지
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    • 제9권6호
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    • pp.589-594
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    • 1999
  • The effect of $\beta$-heat treatment on th microstructure, mechanical properties and texture in the nuclear fuel cladding of Zircaloy-4 tubes was chosen at 1000, 1100 and 120$0^{\circ}C$, and the tubes were heat-treated by a high frequency vacuum induction furnace. Morphology of the second phase particles and $\alpha$-grain of as-received tubes were markedly changed by heat treatment. The average sizes of second phase particles of as-received and $\beta$-heat treated tubes were 0.1$\mu\textrm{m}$ and 0.076$\mu\textrm{m}$, respectively. However, the average sizes of second phase particles were not much changed in the $\beta$-heated temperatures. With increasing heat treatment temperatures, the 0.2% yield strength and the hoop strength were decreased because of changes in preferred orientation as will as $\alpha$-plate width. Heat treated Zircaloy-4 tubes exhibited texture changes but the preferred orientation of grains still remained.

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열처리조건과 기판이 $ZnGa_O_4:Mn$ 박막 형광체의 발광특성에 미치는 영향 (Effects of heat treatment and substrates on luminescent characteristics of $ZnGa_O_4:Mn$ thin film phosphor)

  • 정승묵;김영진
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.181-184
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    • 2004
  • The green emitting phosphor, $ZnGa_2O_4:Mn$ thin film with spinel structure were deposited by rf magnetron sputtering. Thin film phosphors were heat-treated in nitrogen, vacuum and air atmosphere, respectively. The effects of the substrates, heat-treatment conditions and the sputtering parameters were investigated. The growing behavior and luminescent properties of thin films depend on the crystallinity of the substrates. The Ga/Zn atomic ratios and luminescent characteristics were dependent on the annealing conditions.

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플라즈마 용해법에 의한 ZrO$_2$-Y$_2$O$_3$ 피복층의 가열처리효과 (The heat treatment characteristics of plasma sprayed ZrO$_2$-Y$_2$O$_3$ coatings)

  • 정병근;김한삼;김수식
    • 한국표면공학회지
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    • 제27권1호
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    • pp.12-18
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    • 1994
  • The plasma spray process was used to deposit coatings of $ZrO_2$-8wt%Y2O3 powders on mild steel sub-strate, and the characteristics of as-deposited and heat treated coatings have been investigated. Particulary, the variations of porosity, wear resistance, thermal barrier and thermal shock resistance in $ZrO_2$-8wt% $Y_2O_3$coatings after heat treatment under vacuum circumstance have been investigated. The porosity of the coating layer was increased with increased spray distance. In the case of the arc current of 450A and at the spray distance of 50mm, it was obtained the lowest amount of porosity. After heat treatment, the amount of porosity was found to be decreased, and the wear resistance, microhardness and thermal shock resistance were im-proved. However, the thermal barrier was decreased.

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BIOCOMPATIBISITY OF ION BEAM PROCESSED FILMS DEPOSITED ON SURGICAL TI-6AI-4V

  • Lee, I-S;Song and I-j Yu
    • 한국진공학회지
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    • 제6권S1호
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    • pp.16-22
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    • 1997
  • ion beam processing of materials for medical application has gained increasing interest in the last decade and the implantation of nitrogen into TI-6AI-4V to improve corrosive-wear performance is currently used for processing of total hip and knee joints. Oxides and nitrides of Ti, Zr, Al, Cr were deposited on TI-6AI-4V substrates by DC magnetron sputtering dual ion beam sputtering and ion beam assisted deposition. The cytotoxicity of these films were investigated by MTT method and showed comparable to untreated TI-6AI-4V Plasm-sprayed hydroxyapatite(HAp) coatings showed excellent cytotoxicity regardless of heat treatment. intermediate layer coatings of nitrides and oxides increased the bond strength of HAp to substrate by intrdducing chemical bond at interface. Heat treatment of HAp coatings also improved the chemical bond at interfaces and increased the bond strength of untreated TI-6AI-4V to 16.4 kg/$\textrm{cm}^2$ but still lower than 33.1 kg./$\textrm{cm}^2$ of ir oxide as a imtermediate layer caoting.

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[RCOOH]-$\varepsilon$-Caprolactam-Montmorillonite 층간화합물의 합성과 고진공상태하에서의 등온 분해에 관한 연구 (A Study on the Synthesis of [RCOOH]-$\varepsilon$-Caprolactam-Montmorillonite Intercalations-complex and its Isothermal Decomposition in High Vacuum)

  • 조성준
    • 한국세라믹학회지
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    • 제33권8호
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    • pp.909-914
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    • 1996
  • In this research [RCOOH]-$\varepsilon$-Caprolactam-Montmorillonite was synthesized by reaction between Na-Mont-morillonite (10-Carboxy-n-decyl)dimethylethylammonium (=RCCOH) ion and $\varepsilon$-Caprolactame-Motmorillonite ob-tained was 3.62$\AA$ After heat treatment of this intercalations complex at 37$^{\circ}C$ in high vacuum for 12 h 24 h, 40 h and 90 h the basal spacing was reduced to 35.8$\AA$, 34.2, 17.5 $\AA$ and 16.6$\AA$ respectively. The calculated amount of free $\varepsilon$-caprolactame included int he intercaltions complex and that of $\varepsilon$-caprolactame which is interca-lated into the interlayer space of montomorillonite and still remained after heat treatment are 4.6~4.9 and 0.5 molecules per unite cell of montmorillonite respectively.

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Synthesis and Characterization of $Eu^{2+}$ Doped $BaAl_2S_4$ Phosphor by Vacuum Heat Treatment

  • Cho, Yang-Hwi;Park, Do-Hyung;Ahn, Byung-Tae
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.39-42
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    • 2006
  • A $Eu^{2+}$ doped $BaAl_2S_4$ phosphor was synthesized from BaS, EuS, Al and S powder by vacuum heat treatment. The synthesized powder at $850^{\circ}C$ was composed of only $BaAl_2S_4$ phase. The photoluminescence of $Eu^{2+}$ doped $BaAl_2S_4$ phosphor showed the blue emission centered at 470nm and CIE color coordinate at x=0.12, y=0.11.

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Optical Reactivity Modification of Titanium Oxide coatings on Ceramic filters by Nitrogen ion Implantation

  • 김형진;박재원
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.90-90
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    • 2010
  • We investigated the modification of optical response properties of titanium dioxide (TiO2) coatings on the ceramic water-purification filters by using ultraviolet-visible absorption spectroscopy and X-ray diffraction. The TiO2 coatings were prepared on ceramic substrate by e-beam evaporation method. These amorphous TiO2 were turned into anatase phase by heat treatment at $700^{\circ}C$ for 2 hours. The doping of N atoms into the TiO2 coatings was done by using 70KeV of N+ ion implantation with the dose of $1.0{\times}1017$ ions/cm2, followed by post-irradiation heat treatment at $550^{\circ}C$ for 2 hours. Methylene blue test of TiO2 coatings to solar irradiation showed that the post-evaporation heated TiO2 was photocatalytic and N-doped TiO2 reacted to the visible part of solar irradiation.

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AES/XPS를 이용한 Au/V, Au/Ti 박막의 표면산화물 분석 (Characterization of Surface Oxides in Gold Thin Films with V- and Ti- underlays by AES and XPS)

  • Kim, Jin -Young
    • 한국진공학회지
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    • 제1권1호
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    • pp.100-105
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    • 1992
  • Au/V, Au/Ti의 이중구조 박막을 대기 중에서 $500^{\circ}C$에서 열처리한 후 Auger electron spectroscopy(AES)와 X-ray photoelectron spectroscepy(XPS)를 이용하여 분석 하였다. 열처리 과정에서 Au와 SiO2 기판 사이의 V-와 Ti- 하층박막은 Au 표면 위에 산화 물을 형성하였다. 산화물의 화학조성은 Au/V, Au/Ti 박막에서 V2O5와 TiO2로 각각 판명되었다.

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XLPE/EPDM laminate의 계면절연파괴괴현상 (Interfacial Breakdown Phenomena in XLPE/EPDM Laminates)

  • 남진호;서광석
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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    • pp.540-543
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    • 1999
  • In order to determine what indluences the interfacial breakdown in EPDM/XLPE laminates. We studied the interfacial breakdown phenomena at several interfacial conditions. Breakdown strength in laminates pasted with silicone oil was higher than that with silicone grease. As a function of heat treatment time in a vacuum, interfacial breakdown strength increased much in XLPE/EPDM laminates pasted with silicone grease but increased a little in that with silcone oil. FT-IR spectrum of silicone oil was similar to that is silicone grease. FT-lR spectrum of silicone oil was not changed by the heat treatment in a vacuum, but in silicone grease another peak appeared.

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