• Title/Summary/Keyword: 미세압출

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Fabrication Process and Prospect of the Ceramic Candle Filter by Ramming Process (래밍성형에 의한 세라믹 캔들 필터 제조공정 및 전망)

  • Seo, Doowon;Han, Insub;Hong, Kiseog;Kim, Seyoung;Yu, Jihang;Woo, Sangkuk
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.113.2-113.2
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    • 2010
  • 세라믹 필터는 여러 종류의 분진제거 시스템에서 연소 배가스 정제를 위한 가장 적절한 소재로 알려져 있다. 현재까지 다양한 형태의 세라믹 필터가 개발되고 있는데, 캔들 타입(candle type), 튜브 타입(tubular type), 평판 타입(parallel flow type) 등이 그 예이다. 통상적으로 세라믹 캔들 필터는 가압유동층복합발전(PFBC, Pressurize Fluidized-Bed Combustion), 석탄가스화복합발전(IGCC, Integrated coal Gasification Combined Cycle), 석탄가스화연료전지복합발전(IGFC, Integrated coal Gasification Fuel cell Combined cycle)에서 고온 배가스 정제용으로 사용되고 있다. 일반적으로 IGCC나 CTL 합성가스 정제시스템의 경우에는 높은 고압(약 25기압)과 미세분진이 함유되어 있는 분위기에서 운전된다. 그러므로 이때 사용되는 초청정용 세라믹 집진필터는 고온, 고압 및 부식 환경에서 50 MPa 이상을 갖는 높은 강도와 내식성을 갖도록 개발되어야 하기 때문에 SiC(Silicon Carbide)가 가장 적절한 캔들 필터 소재로 적용되고 있다. 이에 따라 집진용 SiC 세라믹 캔들 필터를 개발하기 위해서는 고온에서 내산화성이 우수하고, 부피팽창에 의한 균열이 발생하지 않는 무기결합재의 선정 및 이를 통한 소재의 특성 최적화가 가장 중요한 부분이라 할 수 있다. 본 연구에서는 래밍성형 공정을 적용하여 1m급 탄화규소 세라믹 캔들 필터 시작품을 제조하였으며, 래밍성형 공정 이외에 정수압가압성형, 진공압출성형으로 제조되고 있는 세라믹 캔들 필터의 국내외 시장 및 그 전망을 분석하였다.

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A Study on the Removal of Complex Odor including Acetaldehyde and Ozone Over Manganese-based Catalysts (아세트알데히드와 오존 복합악취 저감을 위한 망간기반 촉매 성능 연구)

  • Seo, inhye;Lee, Minseok;Lee, Sooyoung;Cho, Sungsu;Uhm, Sunghyun
    • Applied Chemistry for Engineering
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    • v.28 no.2
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    • pp.193-197
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    • 2017
  • In this study, we report on the catalyst process installed in conjunction with a wet plasma electrostatic precipitator to remove the oil mist and fine dust emitted from large-size grill restaurants. The multi-stage catalyst module reduced odor through catalytic reaction of acetaldehyde on catalysts even at an ambient temperature with ozone as an oxidant readily produced in a wet plasma electrostatic precipitator. Two types of manganese-based catalysts, $Mn_2O_3$ and $CuMnO_x$ were fabricated by extrusion molding for structured catalysts in practical applications, and the optimum conditions for high removal efficiencies of acetaldehyde and ozone were determined. When two optimized catalysts were applied in a two-stage catalyst module, the removal efficiency of acetaldehyde and ozone were ${\geq}85%$ and 100% respectively at the space velocity of $10,000h^{-1}$ and the reaction temperature of $100^{\circ}C$.

Effect of Heat Treatment on the Microstructure and Mechanical Properties for Al-Si Alloyed Powder Material by Gas Atomizing and Hot Extrusion Process (가스 분무 공정에 의해 제조된 Al-Si 합금 분말 압출재의 열처리에 의한 미세조직 및 기계적 특성 변화)

  • Nam, Ki-Young;Jin, Hyeong-Ho;Kim, Yong-Jin;Yoon, Seog-Young;Park, Yong-Ho
    • Journal of Powder Materials
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    • v.13 no.6 s.59
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    • pp.421-426
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    • 2006
  • The microstructural and mechanical properties of Al-Si alloyed powder, prepared by gas atomization fallowed by hot extrusion, were studied by optical and scanning electron microscopies, hardness and wear testing. The gas atomized Al-Si alloy powder exhibited uniformly dispersed Si particles with particle size ranging from 5 to $8{\mu}m$. The hot extruded Al-Si alloy shows the average Si particle size of less than $1{\mu}m$. After heat-treatment, the average particle size was increased from 2 to $5{\mu}m$. Also, mechanical properties of extruded Al-Si alloy powder were analyzed before and after heat-treatment. As expected from the microstructural analysis, the heat-treated samples resulted in a decrease in the hardness and wear resistance due to Si particle growth. The friction coefficient of heat-treated Al-Si alloyed powder showed higher value tough all sliding speed. This behavior would be due to abrasive wear mechanism. As sliding speed increases, friction coefficient and depth and width of wear track increase. No significant changes occurred in the wear track shape with increased sliding speed.

The Texturization Properties of Textured Extrudate made by a Mixture of Rice Flour and Isolated Soybean Protein (쌀과 분리대두단백 혼합에 따른 조직화 특성)

  • Han, Ouk;Park, Yong-Ho;Lee, Sang-Hyo;Lee, Hyun-Yu;Min, Byong-Lyoung
    • Korean Journal of Food Science and Technology
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    • v.21 no.6
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    • pp.780-787
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    • 1989
  • The texturization properties of extrudate from isolated soybean protein and rice flour by extrusion cooking were investigated. The addition of up to 30% rice flur to isolated soy proetin could give more tenderness to the texturized extrudate. As the rice flour content increased, die temperature, nitrogen solubility index, and integrity index were decreased slightly with lower chewiness and gumminess. The water content of final extrudate was increased as the addition of rice flour increased, while density was maintained without variation, and rehydration ratio was decreased. The distribution of pressure profile during extrusion were in the range of $15-100kg/cm^3$. As the addition of rice flour increased, scanning electron micrographs demonstrated the gelatinized surface structure of rice starch and the increased air cell size of the testurized extrudate.

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Properties of Advanced Synthetic Fiber Reinforced Concrete for Improvement of Tunnel Shotcrete Performance (터널 숏크리트 성능 향상을 위한 고기능성 합성섬유 보강 콘크리트의 물성 평가)

  • Jeon, Chanki;Jeon, Joongkyu
    • Journal of the Society of Disaster Information
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    • v.7 no.1
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    • pp.43-50
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    • 2011
  • The Application of Steel Fiber Shotcrete in tunneling construction has become part of tunneling practice at least since the 1970s because of its high bending and tensile properties. Over the past 3 decades, researcher from all over the world have been significantly developing the associated technologies for improved performance of SFRS. But still it has some major drawbacks in terms of durability, damage of pumping hose, wastage due to rebound concrete, corrosion and it costs high. To overcome this situation researcher has to look for some alternative material. Therefore, this part study deals with the three types of fiber in order to find good alternative for steel fiber. Polyamide and Polypropylene fiber were used in this study with 0.6, 0.5% mixing ratio. To evaluate its fresh and harden properties air content, slump, compressive, split tensile and bending strength were measured. After comparing the results of all three types of fiber reinforced concrete with its different mixing proportion this study propose that polyamide fiber with addition ratio of 0.6 % for field use.

Fabrication and Characteristics of Anode-Supported Tube for Solid Oxide Fuel Cell (습식법에 의한 고체산화물 연료전지용 연료극 지지체관의 제조 및 특성 연구)

  • Kim, Eung-Yong;Song, Rak-Hyeon;Im, Yeong-Eon
    • Korean Journal of Materials Research
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    • v.10 no.10
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    • pp.659-664
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    • 2000
  • To develop anode-supported tubular cell with proper porosity, we have investigated the anode substrate and t the electrolyte-coated anode tube. The anode substrate was manufactured as a function of carbon content in the range of 20 to 50 vol.%. As the carbon COntent increased, the porosity of the anode substrate increased slightly and the carbon c content with proper porosity is found to be 30 vol.%. The anode-supported tube was fabricated by extrusion process a and the electrolyte layer was coated on the anode tube by slurry coating process. The anode-supported tube was cofired successfully at $^1400{\circ}C$ in air. The porosity of the anode tube was 35%. From the gas permeation test, the anode t tube was found to be porous enough for gas supply. On the other hand, the anode-supported tube with electrolyte layer indicated a very low gas permeation rate. This means that the coated electrolyte was dense.

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Evolution of Microstructure in Al-4.0%Zn-1.5%Mg-0.9%Cu Alloy by Extrusion, Rolling and Heat Treatment (Al-4.0%Zn-1.5%Mg-0.9%Cu 합금의 압출, 압연 및 열처리에 따른 미세조직 변화)

  • Kwon, Hyeok Gon;Park, Jong Moon;Oh, Myung Hoon;Park, No Jin
    • Journal of the Korean Society for Heat Treatment
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    • v.31 no.2
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    • pp.41-48
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    • 2018
  • In this study, microstructural changes due to extrusion, rolling and heat treatment were studied to fabricate Al-4.0wt%Zn-1.5wt%Mg-0.9wt%Cu alloys with homogeneous microstructure suitable for metal cases of smart phones and electronic products fabricated through plastic working. After extrusion microstructure and texture were developed very differently on the surface and inside. Inside, coarse grains were formed and a strong Cube component orientation was developed. On the surface, a weak texture was developed with small grains. After 72% cold rolling the intensity of the Cube component orientation was lower, and uniform texture was developed in all the layers and the R-value was uniformly predicted. After recrystallization, the grain size difference between at the surface and the inside is smaller, when 72% rolling was performed, indicating that a uniform structure is formed. Texture develops almost randomly after recrystallization and exhibits uniform R-values at all layers.

Microstructure and Wear Properties in an Engine Oil Environment of Extruded Hyper-eutectic Al-15wt.%Si Alloy and Gray Cast Iron (과공정 Al-15wt.%Si 압출재와 회주철의 미세조직 및 엔진 오일 환경에서의 마모 특성)

  • Kang, Y.J.;Kim, J.H.;Hwang, J.I.;Lee, K.A.
    • Transactions of Materials Processing
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    • v.27 no.6
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    • pp.339-346
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    • 2018
  • This study investigated the microstructure and wear properties of extruded hyper-eutectic Al-Si (15wt.%) alloy in an engine oil environment. The wear mechanism of the material was also analyzed and compared to conventional gray cast iron. In microstructural observation results of Al-15wt.%Si alloy, primary Si phase ($45.3{\mu}m$) and eutectic Si phase ($3.1{\mu}m$) were found in the matrix, and the precipitations of $Mg_2Si({\beta}^{\prime})$, $Al_2Cu({\theta}^{\prime})$ and $Al_6(Mn,Fe)$ were also detected. In the case of gray cast iron, ferrite and pearlite were observed. It was also observed that flake graphite ($20-130{\mu}m$) were randomly distributed. Wear rates were lower in the Al-Si alloy as compared to those of gray cast iron in all load conditions, confirming the outstanding wear resistance of Al-15wt.%Si alloy in engine oil environment. In the $4kg_f$ condition, the wear rate of gray cast iron was $6.0{\times}10^{-5}$ and that of Al-Si measured $0.8{\times}10^{-5}$. The microstructures after wear of the two materials were analyzed using scanning electron microscope (SEM) and electron backscatter diffraction (EBSD). The primary Si and eutectic Si of Al-Si alloy effectively mitigated the abrasive wear, and the Al matrix effectively endured to accept a significant amount of plastic deformation caused by wear.

Microstructure and High-Cycle Fatigue Properties of High-Speed-Extruded Mg-5Bi-3Al Alloy (Mg-5Bi-3Al 마그네슘 고속 압출재의 미세조직과 고주기피로 특성)

  • Cha, J.W.;Jin, S.C.;Park, S.H.
    • Transactions of Materials Processing
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    • v.31 no.5
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    • pp.253-260
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    • 2022
  • In this study, the microstructural characteristics of a high-speed-extruded Mg-5Bi-3Al (BA53) alloy and its tensile, compressive, and high-cycle fatigue properties are investigated. The BA53 alloy is successfully extruded at a die-exit speed of 16.6 m/min without any hot cracking using a large-scale extruder for mass production. The homogenized BA53 billet has a large grain size of ~900 ㎛ and it contains fine and coarse Mg3Bi2 particles. The extruded BA53 alloy has a fully recrystallized microstructure with an average grain size of 33.8 ㎛ owing to the occurrence of complete dynamic recrystallization during high-speed extrusion. In addition, the extruded BA53 alloy contains numerous fine lath-type Mg3Bi2 particles, which are formed through static precipitation during air cooling after exiting the extrusion die. The extruded BA53 alloy has a high tensile yield strength of 175.1 MPa and ultimate tensile strength of 244.4 MPa, which are mainly attributed to the relative fine grain size and numerous fine particles. The compressive yield strength (93.4 MPa) of the extruded BA53 alloy is lower than its tensile yield strength, resulting in a tension-compression yield asymmetry of 0.53. High-cycle fatigue test results reveal that the extruded BA53 alloy has a fatigue strength of 110 MPa and fatigue cracks initiate at the surface of fatigue test specimens, indicating that the Mg3Bi2 particles do not act as fatigue crack initiation sites. Furthermore, the extruded BA53 alloy exhibits a higher fatigue ratio of 0.45 than other commercial extruded Mg-Al-Zn-based alloys.

Study on the Microstructure Evolution during Extrusion of Zn-Al-Mg alloy (Zn-Al-Mg 합금의 압출 시 미세조직 변화에 관한 연구)

  • W. G. Seo;K. Thool;H. N. Lee;D. J. Yang;S. G. Park;S. H. Choi
    • Transactions of Materials Processing
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    • v.32 no.6
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    • pp.344-351
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    • 2023
  • The use of Zn-Al-Mg alloy coatings for enhancing the corrosion resistance of steel sheets is gaining prominence over traditional Zn coatings. There is a growing demand for the development of thermal spray wires made from Zn-Al-Mg alloys, as a replacement for the existing wires produced using Al and Zn. This is particularly crucial to secure corrosion resistance and durability in the damaged areas of coated steel sheets caused by deformation and welding. This study focuses on the casting and extrusion processes of Zn-2Al-1Mg alloy for the fabrication of such spray wires and analyzes the changes in microstructure during the extrusion process. The Zn-2Al-1Mg alloy, cast in molds, was subjected to a heat treatment at 250 ℃ for 3 hours prior to extrusion. The extrusion process was carried out by heating both the material and the mold up to 300 ℃. Microstructural analysis was conducted using FE-SEM and EDS to differentiate each phase. The mechanical properties of the cast specimen were evaluated through compression tests at temperatures ranging from 200 to 300 ℃, with strain rates of 0.1 to 5 sec-1. Vickers hardness testing was utilized to assess the inhomogeneity of mechanical properties in the radial direction of the extruded material. Finite Element Analysis (FEA) was employed to understand the inhomogeneity in stress and strain distribution during extrusion, which aids in understanding the impact of heterogeneous deformation on the microstructure during the process.