• 제목/요약/키워드: Powder technology

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Computer Aided Engineering Design of Power Injection Molding Process for Dental Scaler Top Mold Design

  • Hwang, C.J.;Ko, Y.B.;Park, H.P.;Chung, S.T.;Rhee, B.O.
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.497-498
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    • 2006
  • Powder Injection Molding (PIM) has recently been recognized as an advanced manufacturing technology for low-cost mass production of metal or ceramic parts of complicated geometry. With this regards, design technology of dental scaler tip PIM mold, which has complex shape, with the help of computer-aided analysis for powder injection molding process was developed. Compter aided analysis results, such as filling pattern, weldline formation, and air vent position prediction were investigated and eventually showed good agreements with experimental results.

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임계상대밀도 모델을 이용한 분말 등통로각압축 공정시 분말 치밀화 거동 (Analysis of Densification Behavior during Powder Equal Channel Angular Pressing using Critical Relative Density Model)

  • 복천희;유지훈;윤승채;김택수;천병선;김형섭
    • 한국분말재료학회지
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    • 제15권5호
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    • pp.365-370
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    • 2008
  • In this study, bottom-up powder processing and top-down severe plastic deformation processing approaches were combined in order to achieve both full density and grain refinement with least grain growth. The numerical modeling of the powder process requires the appropriate constitutive model for densification of the powder materials. The present research investigates the effect of representative powder yield function of the Shima-Oyane model and the critical relative density model. It was found that the critical relative density model is better than the Shima-Oyane model for powder densification behavior, especially for initial stage.

분말단조법에 의한 알루미늄 합금 피스톤 개발 (The Development of Aluminium Alloy Piston by Powder Forging Method)

  • 강대용;박종옥;김길준;김영호;조진래;이종헌
    • 한국정밀공학회지
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    • 제17권8호
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    • pp.87-93
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    • 2000
  • Powder Forging technology is being developed rapidly because of its economic merits and the possibility of lightening parts by replacing steel parts with aluminum ones especially in automotive parts manufacturing. Recently Powder Forging process is widely used for manufacturing primary mechanical parts as a combined technology of P/M and precision hot forging. This paper describes the process conditions for the powder forging of Aluminium alloy piston. For example powder alloy design preform design by FEM simulation cold of compaction of specimens and preform sintering of preform powder forging process. The characteristics of sintered compaction of specimens and preform sintering of preform powder forging process. The characteristics of sintered products and final forged piston ones are investigated with tensile strength hardness ductility and so on. Eventually its results prove the improve mechanical properties of the piston produced by powder forging.

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유한요소해석을 이용한 알루미늄분말단조 피스톤 성형해석에 관한 연구 (A Study of the FEM Forming Analysis of the Al Power Forging Piston)

  • 김호윤;박철우;김현일;박경서;김영호;조호성
    • 대한기계학회논문집A
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    • 제34권10호
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    • pp.1543-1548
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    • 2010
  • 분말단조 공정은 정형의 자동차부품을 제작하는데 널리 이용되고 있다. 분말야금이란 금속 원료 분말을 사용하여 원하는 제품의 형태로 성형을 한 다음 적정온도에서 소결하여 필요한 금속 제품을 제조하는 기술을 말한다. 본 연구에서는 자동차 엔진의 경량화를 위한 피스톤 제작에 관한 것이다. 분말단조로 제작 되어진 엔진 피스톤의 특성을 유한요소해석을 통해서 알아보겠다. 유한요소해석은 DEFORM/3D 를 이용해서 성형성을 평가하도록 하겠다. 성형온도, 구배각도, 마찰계수의 변화에 따른 피스톤의 성형성을 알아보겠다.

Shearing Properties of Hard Metal Powder and Iron Powder in the Low Density Range

  • Jonsen, P.;Haggblad, H.A.
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.1296-1297
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    • 2006
  • Both plastic and elastic properties change dramatically from the beginning to the end of the compaction phase. Previous investigations have shown that powder transfer and high powder flow during initial compaction at low density affects the strength of the final component significantly. Investigated here are shear failure and elastic shear modulus in the low density range for hard metal powder and for pre-alloyed water atomized iron powder. Direct shear test equipment for sand and clay has been modified to measure the shearing properties of powder for an axial loading between 1 kPa and 500 kPa.

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콜라겐 분말 첨가에 따른 국수의 품질 특성 (Quality Characteristics of Noodles prepared by Adding Collagen Powder)

  • 권은령;권남이;박금순
    • 동아시아식생활학회지
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    • 제23권6호
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    • pp.760-767
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    • 2013
  • This study investigated the quality of noodles containing different amounts of collagen powder. Noodles were prepared at ratios of 1, 3, 5 and 7% collagen power based on flour weight. The water binding capacity of the collagen powder was higher than that of flour. The rate of weight increase and volume increase of the noodles as well as the pH and turbidity of the soups were significantly increased with increasing amounts of collagen powder. The noodles showed decreased L and a values, and increased b values with increasing collagen powder in the flour composite. Hardness, springiness and chewiness of cooked noodles increased significantly with the increase in collagen powder content. cohesiveness and brittleness decreased with increasing amounts of added collagen powder. DPPH radical scavenging activity was improved significantly the addition of the collagen powder. Finally sensory evaluation results indicated that the noodles containing 1, 3% collagen powder had higher quality as compared to the other samples. Overall the results suggest that collagen powder is effective for improving the appearance and texture of noodles.

초음파 분무 열분해 공정과 질화처리를 이용한 GaN 분말의 합성과 광학적 성질 (Synthesis and Optical Property of GaN Powder Using an Ultrasonic Spray Pyrolysis Process and Subsequent Nitridation Treatment)

  • 지명준;유재현;이영인
    • 한국분말재료학회지
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    • 제25권6호
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    • pp.482-486
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    • 2018
  • Despite numerous advances in the preparation and use of GaN, and many leading-edge applications in lighting technologies, the preparation of high-quality GaN powder remains a challenge. Ammonolytic preparations of polycrystalline GaN have been studied using various precursors, but all were time-consuming and required high temperatures. In this study, an efficient and low-temperature method to synthesize high-purity hexagonal GaN powder is developed using sub-micron $Ga_2O_3$ powder as a starting material. The sub-micron $Ga_2O_3$ powder was prepared by an ultrasonic spray pyrolysis process. The GaN powder is synthesized from the sub-micron $Ga_2O_3$ powder through a nitridation treatment in an $NH_3$ flow at $800^{\circ}C$. The characteristics of the synthesized powder are systematically examined by X-ray diffraction, scanning and transmission electron microscopy, and UV-vis spectrophotometer.

Effect of Red Pepper (Capsicum frutescens) Powder or Red Pepper Pigment on the Performance and Egg Yolk Color of Laying Hens

  • Li, Huaqiang;Jin, Liji;Wu, Feifei;Thacker, Philip;Li, Xiaoyu;You, Jiansong;Wang, Xiaoyan;Liu, Sizhao;Li, Shuying;Xu, Yongping
    • Asian-Australasian Journal of Animal Sciences
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    • 제25권11호
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    • pp.1605-1610
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    • 2012
  • Two experiments were conducted to study the effects of red pepper (Capsicum frutescens) powder or red pepper pigment on the performance and egg yolk color of laying hens. In Exp. 1, 210, thirty-wk old, Hy-line Brown laying hens were fed one of seven diets containing 0.3, 0.6, 1.2, 2.0, 4.8 or 9.6 ppm red pepper pigment or 0.3 ppm carophyll red. Each diet was fed to three replicate batteries of hens with each battery consisting of a row of five cages of hens with two hens per cage (n = 3). In Exp. 2, 180, thirty-wk old, Hyline Brown laying hens, housed similarly to those in Exp. 1, were fed an unsupplemented basal diet as well as treatments in which the basal diet was supplemented with 0.8% red pepper powder processed in a laboratory blender to an average particle size of $300{\mu}m$, 0.8% red pepper powder processed as a super fine powder with a vibrational mill ($44{\mu}m$) and finally 0.8% red pepper powder processed as a super fine powder with a vibrational mill but mixed with 5% $Na_2CO_3$ either before or after grinding. A diet supplemented with 0.3 ppm carophyll red pigment was also included (n = 3). In both experiments, hens were fed the red pepper powder or pigment for 14 days. After feeding of the powder or pigment was terminated, all hens were fed the basal diet for eight more days to determine if the dietary treatments had any residual effects. In Exp. 1, there were no differences in egg-laying performance, feed consumption or feed conversion ratio due to inclusion of red pepper pigment in the diet. Average egg weight was higher (p<0.05) for birds fed 1.2, 2.4 or 9.6 ppm red pepper pigment than for birds fed the diet containing 0.3 ppm red pepper pigment. On d 14, egg color scores increased linearly as the level of red pepper pigment in the diet increased. In Exp. 2, feeding red pepper powder did not affect egg-laying performance, feed consumption or feed conversion ratio (p>0.05). However, compared with the control group, supplementation with all of the red pepper powder treatments increased egg weight (p<0.05). All the red pepper powder treatments also increased (p<0.05) the yolk color score compared with the control. The results of the present study suggest that both red pepper powder and pigment are effective feed additives for improving egg yolk color for laying hens.

β-SiC 분말 Seeds가 Sol-gel 공정으로 합성된 고순도 β-SiC 분말 형상 및 크기에 미치는 영향 (Effects of β-SiC Particle Seeds on Morphology and Size of High Purity β-SiC Powder Synthesized using Sol-Gel Process)

  • 김규미;조경선;박상환
    • 한국세라믹학회지
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    • 제46권5호
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    • pp.528-533
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    • 2009
  • High purity $\beta$-SiC powders were synthesized using sol-gel processing. TEOS and phenol resin were used as the starting material for the silicon source and carbon source, respectively. The process turned out to be capable of producing high purity SiC powder purity degree with 99.98 %. However, it was difficult to control the shape and size of $\beta$-SiC powders synthesized by sol-gel process. In this study, $\beta$-SiC powder with size of $1{\sim}5$ um an 30 nm were used as the seeds for $\beta$-SiC to control the $\beta$-SiC powder morphology. It was found that $\beta$-SiC powder seeds was effective to increase the powder average size of synthesized $\beta$-SiC using sol-gel process by acting as the preferred growing sites for $\beta$-SiC.

자전연소합성법을 이용한 Cr 분말 제조시 산세조건에 따른 물성평가 (Effect of Acid Leaching Conditions on the Properties of Cr Powder Produced by Self-propagating High-temperature Synthesis)

  • 이용관;조영우;최신영;허성규;주원;박경태;이미혜;심재진
    • 한국분말재료학회지
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    • 제30권3호
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    • pp.233-241
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    • 2023
  • In this study, we evaluated the effects of acid leaching on the properties of Cr powder synthesized using self-propagating high-temperature synthesis (SHS). Cr powder was synthesized from a mixture of Cr2O3 and magnesium (Mg) powders using the SHS Process, and the byproducts after the reaction were removed using acid leaching. The properties of the recovered Cr powder were analyzed via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), particle size analysis (PSA), and oxygen content analysis. The results show that perfect selective leaching of Cr is challenging because of various factors such as incomplete reaction, reaction kinetics, the presence of impurities, and incompatibility between the acid and metal mixture. Therefore, this study provides essential information on the properties under acidic conditions during the production of high-quality Cr powder using a self-propagating high-temperature synthesis method.