• Title/Summary/Keyword: properties of the powder

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Magnetic Properties and Workability of Fe-Si Alloy Powder Cores

  • Lee, Tae-Kyung;Kim, Gu-Hyun;Choi, Gwang-Bo;Jeong, In-Bum
    • Journal of Magnetics
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    • v.13 no.4
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    • pp.170-172
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    • 2008
  • Fe-6.5% Si alloys have good magnetic properties due to their high electrical resistivity, very low magneto-striction, and low crystalline anisotropy. Despite their strong potential, these alloys have seldom been used in magnetic applications because of the very poor ductility of Si-steel above 3.0 wt% Si [1-4]. It is difficult to achieve compressed Fe-6.5% Si powder cores with excellent properties because of the low density due to poor ductility. In compressed powder cores, high density is essential in order to obtain high magnetization and permeability. In this study, an attempt was made to produce Fe-3%Si powder cores because the Fe-3.0 wt% Si alloys have relatively good magnetic properties and room temperature ductility. Gas atomized Fe-3.0 wt% Si powder was compressed into toroid shape cores. By reducing the Si content to 3.0 wt%, the hysteresis loss could be greatly reduced and thus the total core loss could be minimized. The total core loss is 600 mW/$cm^3$ at 0.1 T and 50 kHz.

The Influence of Production Process Parameters on Properties W-Ag, Mo-Ag Composites

  • Lezanski, Jan;Madej, Marcin
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1200-1201
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    • 2006
  • Attempts have been made to describe the influence of production process parameters on the microstructure and properties of W-Ag and Mo-Ag composites. The compositions of powder mixtures are W+30% Ag and Mo+30%Ag. Silver additions assists densification during sintering by a liquid phase sintering process. The main goal of this work is to compare properties and microstructure of as-sintered and as-infiltrated composites.

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Synthesis and Characteristics of FePt Nanopowder by Chemical Vapor Condensation Process

  • Yu, Ji-Hun;Lee, Dong-Won;Kim, Byoung-Kee;Jang, Tae-Suk
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1196-1197
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    • 2006
  • FePt binary-alloy nanopowder has been successfully synthesized by chemical vapor condensation process with two metal organic precursors, i.e., iron pentacarbonyl and platinum acetylacetonate. Average particle size of the powder was less than 50 nm with very narrow size distribution, revealing high dispersion capability. Characteristics of the powder could be controlled by changing process parameters such as reaction temperature, chamber pressure, as well as gas flow rate. Magnetic properties of the synthesized FePt nanopowder were investigated and analyzed in terms of the powder characteristics.

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A Study on Properties of High Fluidity Concrete adding Waste Marble Powder (폐대리석 분말을 혼입한 고유동 콘크리트의 특성)

  • Jeong, Euy-Chang;Lee, Yong-Moo;Kim, Young-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.262-263
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    • 2014
  • The purpose of this study was to investigate properties of high fluidity concrete adding waste marble powder. A change in the replacement ratios of waste marble powder was measured compressive strength and slump flow, O-Lot and U-Box. Waste marble powder has replaced binder of high fluidity concrete at certain contents of 0~20%. As a results, Slump flow, O-Lot and U-box adding waste marble powder up to 10% have increased by adding waste marble powder. As the concrete with a replacement ratio of waste marble powder up to 10% was found to have a compressive strength superior to that of plain.

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Fluidity and Setting Properties of Cement Paste by Adding of Fluoro Anhydrite and Fly Ash (불산 무수석고와 플라이 애쉬를 첨가한 시멘트 페이스트의 유동성 및 응결특성)

  • 노재성;김도수;홍성수;임계규;임헌성
    • Journal of the Korean Ceramic Society
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    • v.34 no.12
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    • pp.1261-1267
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    • 1997
  • Four kids of powder admixtures(A, B, C, D) based on anhydrite were manufactured by mixing at a fixed rate of II-anhydrite, fly ash and active silica as an industrial by-product. Fluidity properties of cement paste such as mini-slump, apparent viscosity with elapsed time, as well as setting time of cement pastes of these admixtures substituted up to 11wt% of cement were compared to those of cement paste(SS) substisuted by marketed high-strength powder admixture(S). Among these powder admixtures, the fluidity of cement pastes(PA, PC) substituted by A and C powder admixtures manufactured from II-anhydrite and fly ash had an excellent property than that of cement paste substituted by marketed powder admixture and also a good fluidity-retention effect with elapsed time by adding of superplasticizer. The setting time of cement paste substituted by powder admixtures based on anhydrite slightly retarded than that of cement paste substituted by marketed powder admixture.

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Mapping Particle Size Distributions into Predictions of Properties for Powder Metal Compacts

  • German, Randall M.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.704-705
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    • 2006
  • Discrete element analysis is used to map various log-normal particle size distributions into measures of the in-sphere pore size distribution. Combinations evaluated range from monosized spheres to include bimodal mixtures and various log-normal distributions. The latter proves most useful in providing a mapping of one distribution into the other (knowing the particle size distribution we want to predict the pore size distribution). Such metrics show predictions where the presence of large pores is anticipated that need to be avoided to ensure high sintered properties.

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Optimization on Organoleptic Properties of Kochujang with Addition of Persimmon Fruits (감과실을 첨가한 고추장의 관능적 특성 최적화)

  • 이기동;정용진
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.6
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    • pp.1132-1136
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    • 1998
  • The optimum mixing conditions of kochujang(persimmon kochujang) added persimmon puree was optimized by four dimensional response surface methodology. The organoleptic color of persimmon kochujang showed the maximum score in 86.74g red pepper powder, 133.51g persimmon puree and 26.31g salt. The organoleptic aroma persimmon kochujang showed the maximum score in 83.48g red pepper powder, 135.38g persimmon puree and 24.50g salt. The organoleptic taste of persimmon ko chujang showed the maximum score in 85.09g red pepper powder, 133.61g persimmon puree and 25.57g salt. The overall palatability of persimmon kochujang showed the maximum score in 82.99g red pepper powder, 133.10g persimmon puree and 25.47g salt. The optimum mixing conditions for overall orga noleptic properties of persimmon kochujang were 83.00g red pepper powder, 133.00g persimmon puree and 25.00g salt.

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Microstructure and Mechanical Properties of Al/SiCp Particle Reinforced Composite Severely Deformed by ARB Process (ARB법에 의해 강소성가공된 Al/SiCp 입자분산복합재료의 미세조직 및 기계적 특성)

  • Lee Seong-Hee;Kim Hyoung-Wook
    • Journal of Powder Materials
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    • v.13 no.1 s.54
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    • pp.39-45
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    • 2006
  • The $Al/SiC_p$ particle reinforced composite fabricated by a powder-in sheath rolling (PSR) method was severely. deformed by the accumulative roll-bonding (ARB) process. The ARB process was performed up to 8 cycles at ambient temperature without lubricant. The ARBed composite exhibited an ulbricant. grained structure similar to the other ARBed bulky materials. Tensile strength of the composite increased gradually with the number of ARB cycles, but from the 6th cycle it rather decreased slightly. These characteristics of the composite were somewhat different from those of Al powder compact fabricated by the same procedures. The difference in microstructure and mechanical properties between Al powder compact and the composite was discussed.

A Study of the Effect of Tungsten Oxide on W, WC Powder and Alloy Properties

  • Jiang, Cijin;Shen, Paul;Wang, Huan
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.654-655
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    • 2006
  • This is about the effects deoxidization, carbonization and alloying preparation on fine grain W, WC, and grade YG8 powder reduced by "yellow tungsten oxide" and "blue tungsten oxide". The result indicates that yellow tungsten has single composition and blue tungsten oxide has complex composition. With this feature, yellow tungsten oxide got better uniformity and concentration distribution on fine particle size W and WC powder than blue tungsten oxide's. The grade alloy YG8 that made of this W or WC powder has uniform alloy construction, concentrated WC grain distribution and better alloy properties.

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Thermoelectric Properties of PbTe Sintered Body Fabricated by Mechanical Alloying Process (기계적합금화 공정에 의해 제조된 PbTe 소결체의 열전특성)

  • 이길근;정해용;이병우
    • Journal of Powder Materials
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    • v.8 no.2
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    • pp.110-116
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    • 2001
  • Abstract To investigate the effect of mechanical alloying process to thermoelectric properties of PbTe sintered body, Pb-Te mixed powder with Pb : Te : 1 : 1 composition was mechanically alloyed using tumbler-ball mill. Thermoelectric properties of the sintered body were evaluated by measuring of the Seebeck coefficient and specific electric resistivity from the room temperature to 50$0^{\circ}C$. Sintered body of only mechanically alloyed PbTe powder showed p-type behavior at the room temperature, and occurred type transition from p-type to n-type at about 30$0^{\circ}C$. PbTe sintered body which was fabricated using heat treated powder in $H_2$ atmosphere after mechanical alloying showed stable n-type behavior under 50$0^{\circ}C$. N-type PbTe sintered body fabricated by mechanical alloying process had 4 times higher power factor than that fabricated by the melt-crushing process. Application of a mechanical alloying process to fabricate of n-type PbTe thermoelectric material seemed to be useful to increase the power factor of PbTe sintered body.

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