• Title/Summary/Keyword: Powder loss

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Application of cold isostatic pressing method for fabrication of SoG-Si powder compacts (태양전지급 폴리실리콘 성형체 제작을 위한 CIP법의 활용)

  • Lee, Ho-Moon;Shin, Je-Sik;Moon, Byung-Moon;Kwon, Ki-Hwan;Kim, Ki-Young
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.126-129
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    • 2009
  • In this study, it was aimed to develop the re-use technology of ultra-fine silicon powders, by-products during the current production process of high purity poly-Si feedstock. For this goal, the compacts of the silicon powders were tried to fabricate by CIP (Cold Isostatic Pressing) method using silicon rubber mold without chemical binder materials. The density ratio of the silicon powder compacts reached 74%. In order to simulate the actual handling and charging conditions of feedstock material in casting process, a shaking test was carried out and mass loss measured. Finally, the silicon powder compacts were melted using a cold crucible induction melting method and the purity assessment was conducted by Hall effect measurement.

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Effect of Debinding and Sintering Conditions on the Tensile Properties of Water-atomized STS 316 L Parts by Powder Injection Molding (수분무 STS 316L 분말사출성형체의 탈지 및 소결공정에 따른 인장 특성)

  • 윤태식;성환진;안상호;이종수
    • Journal of Powder Materials
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    • v.9 no.4
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    • pp.218-226
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    • 2002
  • The purpose of the present study is to investigate the influence of thermal debinding and sintering conditions on the sintering behavior and mechanical properties of PIMed 316L stainless steel. The water atomized powders were mixed with multi-component wax-base binder system, injection molded into flat tensile specimens. Binder was removed by solvent immersion method followed by thermal debinding, which was carried out in air and hydrogen atmospheres. Sintering was done in hydrogen for 1 hour at temperatures ranging from 1000℃ to 1350℃ The weight loss, residual carbon and oxygen contents were monitored at each stage of debinding and sintering processes. Tensile properties of the sintered specimen varied depending on the densification and the characteristics of the grain boundaries, which includes the pore morphology and residual oxides at the boundaries. The sinter density, tensile strength (UTS), and elongation to fracture of the optimized specimen were 95%, 540 MPa, and 53%, respectively.

Magnetic Properties of FeCuNbSiB Nanocrystalline Alloy Powder Cores Using Ball-milled Powder

  • Kim, G. H.;T. H. Noh;Park, G. B.;Kim, K. Y.
    • Proceedings of the Korean Magnestics Society Conference
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    • 2002.12a
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    • pp.202-203
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    • 2002
  • Ribbon type nanocrystalline alloy cores have shown excellent soft magnetic properties in the high frequency range because of small crystalline anisotropy and nearly zero magnetostriction[1]. In present, however ribbon alloys gives some limit in applications such as a large inductor and reactors of PFC circuit, which are required good DC bias property and low loss in the high frequency. Powder alloys with ultra fine grain structure can be an important way to overcome this kind of disadvantage, and to improve the high frequency soft magnetic properties in conventional metallic powder cores[2]. (omitted)

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Quality Characteristics of Muffins by the Addition of Dried Barley Sprout Powder (보리순 가루를 첨가한 머핀의 품질 특성)

  • Cho, Jung Sun;Kim, Hyeyoung
    • Korean journal of food and cookery science
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    • v.30 no.1
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    • pp.1-10
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    • 2014
  • To evaluate the effect of dried barley sprout powder on muffins, muffins were made after they had been supplemented with barley sprout powder (0, 10, 20 and 30%(all w/w)). The moisture content, crude protein and crude lipid were reduced with an increase in barley sprout powder. The content of crude ash and crude fiber in the control group was significantly lower than those of the samples with barley sprout powder. The pH in the sample with barley sprout powder was lower than that of the control group. The highest specific gravity in the group with 30% of barley sprout powder was 0.84. No significant weight and baking loss rate changes were observed. The sample with no barley sprout powder showed the highest volume. The sample with 30% of barley sprout powder showed the highest uniformity. In color, the L-value and a-value of the control group were significantly higher than those of the other groups. Hardness, gumminess and chewiness of the control group showed the lowest value rather than the other groups. Springness and cohesiveness of the control group were significantly higher than those of the other groups. Crumb color, grass odor and bitter taste showed significant difference among groups. Acceptance of appearance, flavor, taste and total acceptability of groups with 10% and 20% of barley sprout powder did not show any significant difference when compared to the control group. Based on the above results, less than 20% of barley sprout powder would be proper to make muffins.

Quality Characteristics of Rice Pound Cake prepared with Blueberry Powder (블루베리 가루를 첨가한 쌀 파운드케이크의 품질 특성)

  • Lee, Won-Gab;Lee, Jeong-Ae
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.5
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    • pp.577-585
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    • 2013
  • This study investigated the physicochemical and sensory characteristics of rice pound cake prepared with various amounts of blueberry powder. The weight of rice pound cakes with additions of 2~8% blueberry powder increased from 418.58 to 420.50 g. The volume and specific loaf volume of rice pound cakes prepared by adding blueberry powder were lower than those of the control. The baking loss rate for the control was 7.72% and that of rice pound cakes prepared by adding blueberry powder decreased by 6.98~6.56%. The moisture contents of rice pound cakes added with blueberry powder were higher than the control. The pH levels for rice pound cakes prepared with blueberry powder ranged between 6.47 and 7.58 and that of the control was 8.11. The microstructural observation by scanning electron microscopy (SEM) showed well developed air cells of control. DPPH radical scavenging activity of the control group was 13.6%, whereas pound cakes prepared by adding blueberry powder ranged from 35.2~78.8%. The "a" value of redness was increased, but L and b value were decreased significantly by additions of blueberry powder. The full textural properties of rice pound cakes were being significantly increased by additions of blueberry powder. Sensory evaluation scores in terms of appearance, flavor, taste, texture and overall preference for pound cakes showed that 4~6% of substituted sample groups were higher than those of others. The results of this study suggest that additions of 4~6% blueberry powder was the best substitution ratio for rice pound cakes.

Quality Characteristics of Muffin Added with Bitter Melon (Momordica charantia L.) Powder (여주분말을 첨가한 머핀의 품질특성)

  • An, Sang-Hee
    • Korean journal of food and cookery science
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    • v.30 no.5
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    • pp.499-508
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    • 2014
  • The purpose of this study was to examine the qualities of muffins with 0, 3, 6, 9, and 12% bitter melon powder. The specific gravity of muffins prepared by adding bitter melon powder was higher than that of the control group. The height of the control group was higher than that of the samples with bitter melon powder. The weight of muffins was not significantly different between all sample groups. The volume and specific loaf volume of muffins were decreased by the addition of bitter melon powder. The baking loss rate of muffins was not significantly different between all sample groups. The moisture content of the samples with bitter melon powder was higher but the pH of muffins was lower than those of the control group. DPPH radical scavenging activity of the control group was 26.86%, whereas the samples with bitter melon powder ranged from 41.35~74.91%. In crumb color, the L value was decreased, but a and b value were increased significantly by the addition of bitter melon powder. The hardness, springiness, cohesiveness, chewiness and brittleness of textural properties of muffins were significantly decreased by the addition of bitter melon powder. Sensory evaluation scores in terms of appearance, flavor, taste, texture and overall preference of groups with 3% and 6% of bitter melon powder did not show any significant difference when compared to the control group. Based on the above results, using less than 6% of the bitter melon powder would be proper to make muffins.

Sintering Behavior of Ultra-fine Hydroxyapatite Powders Synthesized by Hydrothermal Reaction (수열반응으로 합성한 Hydroxyapatite 초미분말의 소결특성)

  • 최재웅;조성원;최상홀
    • Journal of the Korean Ceramic Society
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    • v.31 no.11
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    • pp.1265-1270
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    • 1994
  • Ultra-fine hydroxyapatite powder were synthesized by the hydrothermal reaction at 10 atm, 3 hrs of Ca(OH)2 suspension with (NH4)2HPO4 solution, and were characterized sintering behavior. Sintered bodies of hydroxyapatite powders which synthesized by hydrothermal reaction method has less weight loss, less sintering shrinkage and superior mechanical property, and was more dense than sintered bodies of hydroxyapatite powder which synthesized by wet method. Sintered bodies were hydroxyapatite single phase. When soack in Ringer's solution for 2 weeks, hydroxyapatite powders preserved hydroxyapatite and sintered body absorbed trace of Ca2+ ion with soaked time.

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