• Title/Summary/Keyword: Mineral Casting

Search Result 24, Processing Time 0.038 seconds

Effects of viscosities of slip on slip casting and properties of sintered bodies of cordierite (Slip의 점도가 slip casting 및 casting 및 cordierite 소결체의 특성에 미치는 영향)

  • Baik Yong-Hyuck;Chang Pok-Kie;Kwak Hyo-Sup
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.15 no.5
    • /
    • pp.202-207
    • /
    • 2005
  • We have investigated the relationship between a viscosity of the slip prepared from kaolin, quartz, $Mg(OH)_2$, etc and its influence on the speed of slip casting and the microsturcture of a sintered body. The speed of slip casting decreases as a viscosity of a slip decreases. The optimized viscosity range of a slip was found to be around $3.0\~17.0\;cP$. By careful controlling a viscosity of slip, homogeneous microstructure of outer surface layers, inner surface layers, intermediate layers, and inside layers were obtained by casting process. The specimen sintered at $1350^{\circ}C$ consists of a cordierite crystalline phase only as a constituent mineral.

Design Technology of High Speed and Precision Machining Center (초곡속 고정밀 머시닝 센터 설계 기술)

  • Kim, Bup-Min;Choi, Won-Sun;Ha, Jae-Young;Kim, Tae-Hyoung
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.28 no.8
    • /
    • pp.869-877
    • /
    • 2011
  • In order to manufacture precision parts which are used for IT and BT Industry by machining, users need higher speed & precision machining center. So, for development of this kind of machine, we designed gantry type machining center which is piling of 3 axes on one moving body and the 2-axis rotary table is fixed on the base. It is applied linear motor that is instead of ball-screw and servo-motor combination and 50,000 rpm high-speed spindle. Composite material structure called mineral casting or resin concrete is applied also. This paper presents design technology and evaluated results of high speed and precision machining center.

Nanowire-Like Copper Oxide Grown on Porous Copper, a Promising Anode Material for Lithium-Ion Battery

  • Park, Hyeji;Lee, Sukyung;Jo, Minsang;Park, Sanghyuk;Kwon, Kyungjung;Shobana, M.K.;Choe, Heeman
    • Journal of the Korean Ceramic Society
    • /
    • v.54 no.5
    • /
    • pp.438-442
    • /
    • 2017
  • This paper reports the facile synthesis of microlamella-structured porous copper (Cu)-oxide-based electrode and its potential application as an advanced anode material for lithium-ion batteries (LIBs). Nanowire-like Cu oxide, which is created by a simple thermal oxidation process, is radially and uniformly formed on the entire surface of Cu foam that has been fabricated using a combination of water-based slurry freezing and sintering (freeze casting). Compared to the Cu foil with a Cu oxide layer grown under the same processing conditions, the Cu foam anode with 63% porosity exhibits over twice as much capacity as the Cu foil (264.2 vs. 131.1 mAh/g at 0.2 C), confirming its potential for use as an anode electrode for LIBs.

A Study on the Changes of Blood Mineral and Enzyme Activity During Growth Period of Velvet Antler in Korean Spotted Deer(Cervus Nippon) (꽃사슴의 녹용 성장기간 중 혈액 내 미네랄 및 효소활성 변화에 관한 연구)

  • Kim, M.H.;Moon, S.H.;Lee, C.H.;Jeon, B.T.
    • Journal of Animal Science and Technology
    • /
    • v.45 no.6
    • /
    • pp.1031-1038
    • /
    • 2003
  • This study was aimed at investigating the change of blood mineral and enzyme activity during growth period of velvet antler in Korean spotted deer. Samples of blood, obtained from the jugular vein of twenty-five deer(4 to 6 year-old males), were taken in 10 days interval from just after casting to 50 days. Deer were randomly selected from the farm, and samples were analyzed for blood parameters like mineral concentration and enzyme activities. No significant differences found in calcium and phosphorus concentration in blood whereas sodium, potassium and chloride concentration were significantly changed with antler growth. There were no significant differences in alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, $\gamma$-glutamyl transferase and lactate dehydrogenase during growth of antler, but alkaline phosphatase concentration was increased with growth of antler, and the highest concentration was obtained on the 50 days after casting. Creatine kinase and lactate dehydrogenase activities for the deer tested in this experiment were higher than those of other animals.

Development and Applications of the Intrinsic Model for Formwork Pressure of Self-Consolidating Concrete

  • Kwon, Seung-Hee;Kim, Jae-Hong;Shah, Surendra P.
    • International Journal of Concrete Structures and Materials
    • /
    • v.6 no.1
    • /
    • pp.31-40
    • /
    • 2012
  • Self-consolidating concrete (SCC) is a recently developed innovative construction material. SCC fills in a formwork without any vibrating consolidation, which allows us to eventually achieve robust casting. However, high formwork lateral pressure exerted by SCC is a critical issue regarding its application as cast-in-place concrete. In order to control the risk caused by high formwork pressure, a comprehensive prediction model for the pressure was previously proposed, investigated, and validated with various SCC mixtures. The model was originally designed to simulate the intrinsic pressure response of SCC mixtures while excluding other extrinsic influencing factors such as friction and flexibility of the formwork. The model was then extended to consider extrinsic factors such as friction between SCC mixtures and formwork. In addition, other interesting topics for peak formwork pressure and mineral admixture effects were summarized in the paper.

A Study of Effecting Factor in the Reology and Physical Properties of Cements (시멘트 유동성과 물성에 미치는 영향인자에 관한 연구)

  • 엄태선;최상흘
    • Journal of the Korean Ceramic Society
    • /
    • v.34 no.10
    • /
    • pp.1027-1036
    • /
    • 1997
  • The reology and several physical properties of cements are studied by varying the different mineral composition and particle size distribution(PSD) of cements with closed circuit ball mill for high workability, low heat of hydration, and high strength. In this study, we found that the workability of concretes is related to the viscosity of cement, and affects to strength. Here, this workability is affected by mineral composition (C3A) and the PSD. Especially, rosin-rammer index and 44${\mu}{\textrm}{m}$ residue in the PSD of cements are affected to water demand, casting property, slump loss, strength of cements. From the above results, the conditions of cement for high workability, low heat of hydration and high strength are to use low C3A clinker, 5-10% slag addition, and to grind cement below 0.7 rosin-rammer index, above 3.5-4.5% 44 ${\mu}{\textrm}{m}$ residue, 4000$\pm$100 $\textrm{cm}^2$/g blaine. Such cements are, therefore, supurior to super low heat cement and slag-blended cement in comparing the physical properties of strength, slump, slump-flow, adiabetic temperature, etc.

  • PDF

Current Status on the Domestic Recycling of Magnesium (국내(國內) 마그네슘 리싸이클링 현황(現況))

  • Park, Hyung-Kyu;Kang, Min-Cheol
    • Resources Recycling
    • /
    • v.20 no.3
    • /
    • pp.3-11
    • /
    • 2011
  • Magnesium has been used as parts of vehicles, case materials of notebook PC and mobile phone, and its demand has been increasing recently. So until now, there has little magnesium scraps from the end of life vehicles or electronic parts, and most scraps has been generated from magnesium processing lines such as melting, die casting and machining. It is to review the present status of magnesium recycling. Here, domestic demand of magnesium, recycling amount and technologies used in domestic recycling companies were surveyed in recent years. In 2010, 8,840 tons of magnesium scraps were processed and used as raw materials for die casting products. The recycling ratio was estimated as 32.5%.