• 제목/요약/키워드: Powder loss

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Nano-scale Inter-lamellar Structure of Metal Powder Composites for High Performance Power Inductor and Motor Applications

  • Kim, Hakkwan;An, Sung Yong
    • Journal of Magnetics
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    • 제20권2호
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    • pp.138-147
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    • 2015
  • The unique nano-scale inter-lamellar microstructure and unparalleled heat treatment process give our developed metal powder composite its outstanding magnetic property for power inductor & motor applications. Compared to the conventional polycrystalline Fe or amorphous Fe-Cr-Si-B alloys, our unique designed inter-lamellar microstructure strongly decreases the intra-particle eddy current loss at high frequencies by blocking the mutual eddy currents. The combination of optimum permeability, magnetic flux and extremely low core loss makes this powder composite suitable for high frequency applications well above 10 MHz. Moreover, it can be also possible to SMC core for high speed motor applications in order to increase the motor efficiency by decreasing the core loss.

Insulation and Magnetic Properties of Iron Powder Coated by Wet Chemical Method

  • Son, Hyeon-Taek;Yun, Cheol-Ho;Cha, Hyun-Rok;Kang, Chang-Seog;Bae, Jung-Chan
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.1167-1168
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    • 2006
  • In this study, the pure iron powder was treated with aqueous phosphoric acid to produce phosphate insulating layer on the surface. After drying the powder, it was compacted in a mold with a diameter of 20mm at 800MPa. The powder compacts were then heat treated at $500^{\circ}C$ for 1 hour. The results showed that insulated iron powder was obtained with uniform phosphate layer by chemical reaction. With increased amount of phosphate layer, the core loss and density of compacts were decreased. It was also found that the addition of ethyl alcohol during insulating reaction resulted in improved core loss value.

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오디 분말을 첨가한 파운드 케이크의 품질 특성 (Quality Characteristics of Pound Cake with Added Mulberry Fruit Powder)

  • 유승석;정현철
    • 동아시아식생활학회지
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    • 제22권2호
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    • pp.239-245
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    • 2012
  • Mulberry fruit powder was substituted for wheat flour in pound cake recipes in amounts of 0%(control), 5%, 10%, 15%, and 20%. We measured the specific gravity of the dough, specific loaf volume, dough yield, baking loss, moisture content, pH, color, identified the texture, and conducted a sensory evaluation for each pound cake. Moisture content increased according to the amount of mulberry fruit powder, but specific gravity, dough yield, and pH decreased. Specific loaf volume and baking loss increased as the amount of mulberry fruit powder increased, but not considerably. The chromatic 'L' and 'b' values were reduced as more mulberry fruit powder was added to more pound cake, While the chromatic 'a' value increased. Texture hardness, springiness, gumminess and chewiness decreased as the pound cake contained more mulberry fruit powder. Cohesiveness did not show any considerable differences beteeen the cakes. A sensory evaluation showed a high preference for the pound cake made with 10% mulberry fruit powder.

Fe계 나노결정립 분말 시트에 첨가된 CNT의 볼밀 공정에 따른 전자파 흡수 특성 변화 (The Characteristic Changes of Electromagnetic Wave Absorption in Fe-based Nanocrystalline P/M Sheets Mixed with Ball-Milled Carbon Nanotubes)

  • 김선이;김미래;손근용;박원욱
    • 한국분말재료학회지
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    • 제16권6호
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    • pp.424-430
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    • 2009
  • Electromagnetic wave energies are consumed in the form of thermal energy, which is mainly caused by magnetic loss, dielectric loss and conductive loss. In this study, CNT was added to the nanocrystalline soft magnetic materials inducing a high magnetic loss, in order to improve the dielectric loss of the EM wave absorption sheet. Generally, the aspect ratio and the dispersion state of CNT can be changed by the pre-ball milling process, which affects the absorbing properties. After the various ball-milling processes, 1wt% of CNTs were mixed with the nanocrystalline $Fe_{73}Si_{16}B_7Nb_{3}Cu_1$ base powder, and then further processed to make EM absorption sheets. As a result, the addition of CNT to Fe-based nanocrystalline materials improved the absorption properties. However, the increase of ball-milling time for more than 1h was not desirable for the powder mixture, because the ballmilling caused the shortening of CNT length and the agglomeration of the CNT flakes.

Effect on the Emulsification Stability and Quality of Emulsified Sausages Added with Wanggasi-Chunnyuncho (Opuntia humifusa f. jeollaensis) Fruit Powders

  • Jeong, Yiji;Han, Youngsil
    • 한국축산식품학회지
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    • 제39권6호
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    • pp.953-965
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    • 2019
  • In this study, the Opuntia humifusa f. jeollaensis (Wanggasi-Chunnyuncho) fruit (WCF) was used as a source of viscous dietary fiber and color pigmentation in sausage production to improve quality characteristics, including cooking loss and emulsion stability. Control and treatment sausages were formulated with 0%, 1%, 5%, and 10% WCF powder, respectively, and the following quality measures were investigated: general composition, fiber content, cooking loss, emulsion stability, chromaticity, pH, texture, and sensory properties. The moisture, dietary fiber, and ash contents showed increasing trends (all p<0.05) with increasing concentrations of fruit powder. Conversely, crude protein and crude fat contents exhibited decreasing trends with increasing fruit powder concentrations (p<0.05). Moreover, both the moisture and dietary fiber contents affected cooking loss, water retention capacity, and the sausage texture, causing the cooking loss to decrease, while the water and oil retention capacity increased (p<0.05) with increasing concentrations of WCF powder. Furthermore, hardness exhibited a significant decreasing trend as the concentration of WCF powder increased (p<0.05). This finding suggested that both dietary fiber and viscous materials, along with the protein and moisture content, affected the product hardness. In addition, sensory evaluation of the WCF powder groups showed better results than did the control group, and the strongest results obtained for the group containing 5% fruit powder (p<0.05). Therefore, this study suggests that WCF powder improves the quality of emulsified sausages and can potentially be applied as a naturally-derived additive.

Powder Blasting 을 이용한 유리의 표면부식시 분사각도의 영향 (Effect of Impact Angle on the Etching of Glass by Powder Blasting)

  • 김광현;박경호;박동삼
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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    • pp.349-354
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    • 2001
  • In this study, we investigated the effect of the impacting ang1e of particles, the scanning times and the stand-off distance on the surface roughness and the weight-loss rate of samples with no mask, and the wall profile and overetching of samples with different mask pattern in powder blasting of soda-lime glass. The varying parameters were the different impact angles between 50$^{\circ}$ and 90$^{\circ}$, scanning times of nozz1e up to 40 and the stand-off distances 70mm and 100mm. The widths of mask pattern were 0.2mm, 0.5mm and 1mm. The powder was alumina sharp particles, WA#600. The mass flow rate of powder during the erosion test was fixed constant at 175g/min and the blasting pressure of powder at 0.2MPa

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Soft-magnetic Characteristics of Co-based Amorphous Powder Produced by Spinning Water Atomization Process (SWAP)

  • Otsuka, I.;Wada, K.;Watanabe, A.;Kadomura, T.;Yagi, M.
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.784-785
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    • 2006
  • Co-based amorphous powder was produced by a new atomization process "Spinning Water Atomization Process (SWAP)", having rapid super-cooling rate. The composition of the alloys was ($(Co_{0.95}Fe_{0.05})_{1-x}Cr_x$)$_{75}Si_{15}B_{10}$ (x=0, 0.025, 0.05, 0.075). The powders became the amorphous state even if particle size was up to about $500{\mu}m$. The coercive force of powders was about 0.35 - 0.7 Oe. Furthermore, Co-based amorphous powder cores with glass binders were made by cold-pressing and sintering methods. The initial permeability of the core in the frequency range up to 100 kHz was about 110, and the core loss at 100 kHz for Bm = 0.1 T was $350kW/m^3$.

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Zn-Al 아크 금속용사 피막을 적용한 구리분말 혼입 시멘트 모르타르의 전자파 차폐 성능 평가 (The Shielding Effectiveness of Zn-Al Arc Thermal Metal Film Coated Cement-Mortar Using Copper Powder)

  • 최현준;최현국;김형철;이한승
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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    • pp.124-125
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    • 2017
  • In this study, the shielding effectiveness of the Zn-Al arc thermal metal film coated cement-mortar mixed with copper powder by reflection, absorption, multi-reflection loss in 2.25~2.65 GHz was reviewed. By enhancing the mixing ratio of copper powder, the shielding effectiveness by absorption and multi-reflection loss was increased, but shielding rate(%) based on 80 dB showed below 20%. The Zn-Al arc thermal metal film coated on specimen, the shielding rate increased 3.5 times by reflection loss.

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코팅제 및 코팅 함량에 따른 철 분말 성형체의 특성 (Properties of compacted iron powder core coated with organic materials)

  • 민복기;김인성;김종령;최성조
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.264-267
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    • 2005
  • Soft magnetic iron powders have been coated with polyester or phenol resin. And the coated powder (soft magnetic composite) have been pressed into ring type core over the pressure of 870 MPa. Green density, magnetic flux density, permeability, core loss of the samples were measured to look at the effect of the coating materials and the amount of them. Green density is increased with the amount of coating materials and shows the maximum value, 6.5 $g/cm^3$ at 5 w/o, but decreased over it. And lowest value of the core loss is showed for the 5 w/o coated samples.

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