• 제목/요약/키워드: powder casting

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Electrochemical Properties of FeS2 Thin Film Electrodes for Thermal Batteries (열전지용 FeS2 박막전극의 전기화학적 특성)

  • Im, Chae-Nam
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.5
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    • pp.318-324
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    • 2017
  • Powder compaction technology is widely used to prepare thermal battery components. This method, however, is limited by the size, thickness, and geometry of the battery components. This limitation leads to excessive cell capacity, overweight, and higher cost of the pellets, which decreases the specific capacities and delays the activation time of thermal batteries. $FeS_2$ thin-film cathodes were fabricated by tape-casting technology and analyzed by SEM and EDS in this paper. The residual organic binder of the $FeS_2$ thin-film cathodes decreased with the temperature of the heat treatment, which improved the specific capacity because of the lower resistance. Specific capacities of the $FeS_2$ thin-film cathodes decreased because of the higher residual binder and the restrictive reaction of active materials with molten salts as the thickness increased. $FeS_2$ thin-film cathodes showed much higher specific capacity (1,212.2 As/g) than pellet cathodes (860.7 As/g) at the optimal heat-treatment temperature ($230^{\circ}C$).

Fabrication of Li2ZrO3 Membrane and Evaluation on the Mechanical Properties Before and After CO2 Separation (Li2ZrO3 분리막의 제조와 이산화탄소 선택투과 전후의 기계적 특성 평가)

  • Park, Sang-Hyun;Lee, Shi-Woo;Yu, Ji-Haeng;Woo, Sang-Kuk;Lee, Kee-Sung
    • Journal of the Korean Ceramic Society
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    • v.44 no.1 s.296
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    • pp.58-64
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    • 2007
  • In this study, we investigated $Li_2ZrO_3$ membrane as a candidate material for high-temperature $CO_2$ separation and evaluated mechanical property. $Li_2ZrO_3$ powder was synthesized by solid state reaction of $Li_2CO_3\;and\;ZrO_2$. Then we fabricated $Li_2ZrO_3$ tape using tape casting method. Dense $Li_2ZrO_3$ membrane prepared by sintering at $1600^{\circ}C$ for 2 h after pressing $Li_2ZrO_3$ tape using lamination machine. Mechanical properties before and after $CO_2$ absorption of fabricated $Li_2ZrO_3$ membrane such as Hertzian indentation, Victors hardness and 3-point bending testing were evaluated.

Shaping and Sintering of $Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3$ System powders by Slurry Process (Slurr법에 의한 $Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3$계 미분말의 성형과 소결성)

  • 김복희;최석홍
    • Journal of the Korean Ceramic Society
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    • v.33 no.11
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    • pp.1267-1275
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    • 1996
  • Green sheet was prepared by tape casting in the composition of (1-x)Pb(Mg1/3Nb2/3)O3-PbTiO3 system using Pb(Mg1/3Nb2/3)O3 and PbTiO3 synthesized with PbO, Nb2O5 MgO and TiO2 The densest green sheet was obtained in the weight ratio 70:30 of powder to binder. Green sheet wasmultilayered in metal mould and formed into lamination at 7$0^{\circ}C$, 300kg/cm2 The lamination was sintered at 110$0^{\circ}C$ 2hr, Dielectric constant and Curie temperature of disc type sintered body was highered with increasing the amount of PbTiO3 and was in the range of 19000-21000, -7~45$^{\circ}C$ respectively. Green and sintered relative density of lamination was 61% and 95% respectively.

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The Effect of Roll Arrangement in the Cold Rolling Mill on the Wear (냉간 압연기용 롤의 배열이 마멸에 미치는 영향)

  • 손영지
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.10a
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    • pp.74-80
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    • 1999
  • Work roll wear in the cold rolling of mild steel strip is strongly affected by rolling materials, rolling conditions such as roll arrangement in the cold rolling mill and lubrication. The tests were performed to find the effects of roll arrangement n the cold rolling mill on the work roll wear under the same lubricating conditions. The obtained results are as follows:If the distance of cold rolling is about 60km, the surface roughness of its was reduced by half(Ra 0.49${\mu}{\textrm}{m}$) and Pc(peak count) also was decreased to 60 ea/cm.It is easier for CC(Continuous casting) to make a slip on rolling than IC(Ingot casting). It is due to surface mirror in which first residual product appears and iron powder included Al2O3 is sticked. Because bending degree of 4Hi-rolling mill is higher than 6Hi-rolling mill, the first surface mirror was occurred to its center-point which is loaded strongly. 6Hi-rolling mill shape-controlled by intermediate roll doesn't need the initial crown to work roll. Therefore, fatigue and wear would appear a little bit.

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A Study on Fabrication of Intermetallic Compounds/Al Matrix Composites by Squeeze Casting (용탕단조법에 의한 금속간화합물/Al기지 복합재료 개발을 위한 기초연구)

  • Choi, Dap-Chun;Lee, Kyung-Ku;Lee, Yeon-O
    • Journal of Korea Foundry Society
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    • v.14 no.5
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    • pp.419-428
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    • 1994
  • The microvickers hardness and microstructure of Fe/Al composite fabricated by squeeze casting method were investigated. Pure Al and A356 Alloy were chosen for the matrix composition and Fe preform was fabricated with sintered Fe powder at $1000^{\circ}C$ for 30min. under hydrogen atmosphere. Experimental variables were included preheating temperature, melt temperature and applied pressure. Analysing the experimental result concerning microstructure of fabricated composites, Fe/A356 composite showed improved microstructure at $600^{\circ}C$ melt temperature and $350^{\circ}C$ preform preheating temperature in Fe distribution and Infiltrated distance. The results of EDX and XRD showed that the interfacial zones of Fe/Al composite were composed of non-equilibrium intermetallic layers[$(Al_5Fe_2)_x$, $Al_{13}Fe_4m\;Fe_3Al$, FeAl]. The microvickers hardness of Fe/Al composite showed higher value than Fe/A356 composite in interface.

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Low Temperature Sintering and Dielectrics Properties of $(Ba_{1-x}Sr_x)TiO_3$ Ceramics by Addition (첨가물에 따른 $(Ba_{0.6}Sr_{0.4})TiO_3$의 저온소결 및 유전특성)

  • Jeon, So-Hyun;Kim, In-Sung;Song, Jae-Sung;Min, Bok-Gi;Yoon, Jon-Do
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.202-203
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    • 2005
  • To recognize whether admixture affects some $(Ba_{0.6}Sr_{0.4})TiO_3$, powder in this research $Li_2CO_3$, MgO, $MnO_2$ adding each 3 wt % by Tape casting method thick film make. Sitering temperature lowered 1300$^{\circ}C$ adding $Li_2CO_3$, and density is 5.942g/$cm^3$, and specific inductive capacity increases about decuple and displayed 4000. Climbed sitering temperature 1400$^{\circ}C$ adding MgO, specific inductive capacity reduced 1/2 times. Lowered sintering temperature 1325$^{\circ}C$ low adding $MnO_2$.

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The Strength of Sintered Body with the Composition and the Forming Process of LTCC Materials (LTCC 소재의 조성과 성형 공정에 따른 소결체의 강도 특성)

  • Gu, Sin Il;Shin, Hyo Soon;Yeo, Dong Hun;Nahm, Sahn
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.1
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    • pp.27-32
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    • 2013
  • According to the composition of LTCC material, though it was thought that bulk defect which was made in forming process effects on the densification during the sintering, it was not reported systemically. In this study, we evaluated crystal structure, 3 point bending strength, hardness and microstructure of the samples by uniaxial pressing and tape casting using the commercial powders of the crystallizing glass and the glass/ceramic composite. In the case of glass/ceramic composite, Viox-001 powder with residual glass in the sintering, 3 point bending strength was similar regardless of forming process due to fill the bulk defect by residual glass. In the case of crystallizing glass, MLS-22, because glass phase was small in the sintering, glass did not fill the pore in the sample by uniaxial pressing process, therefore, the 3 point bending strength of it was 167 MPa. However, the 3 point bending strength of the sample by tape casting was 352 MPa and much higher. Meanwhile, crystal structure and hardness were similar regardless of forming process.

Low Temperature Sintering Properties of $(Ba_{1-X}Sr_x)TiO_3$ Ceramics Added $Li_2CO_3$ ($Li_2CO_3$가 첨가된 $(Ba_{1-X}Sr_x)TiO_3$의 저온소결 특성에 관한 연구)

  • Jeon, So-Hyun;Kim, In-Sung;Song, Jae-Sung;Min, Bok-Gi;Yoon, Jon-Do
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.303-304
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    • 2005
  • Add $Li_2CO_3$ to $(Ba_{0.6}Sr_{0.4})$ $TiO_3$ powder to lower sitering temperature in this research, made thick film by tape casting method. Investigated about sitering temperature and physical properties that added $Li_2CO_3$ Even if lower sitering temperature about $200^{\circ}C$ adding $Li_2CO_3$ 10wt.%, density was near to 5.7$g/cm^3$ that is theoretical values, and crystal structure examined as perobeuseukaiteu senior after sintering.

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Load Relaxation and Creep Transition Behavior of a Spray Casted Hypereutectic Al-Si Alloy (분무 주조 과공정 Al-Si 계 합금의 응력이완 및 Creep 천이 거동)

  • Kim M. S.;Bang W.;Park W. J.;Chang Y. W.
    • Transactions of Materials Processing
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    • v.14 no.6 s.78
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    • pp.502-508
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    • 2005
  • Hypereutectic Al-Si alloys have been regarded attractive for automotive and aerospace application, due to high specific strength, good wear resistance, high thermal stability, low thermal expansion coefficient and good creep resistance. Spray casting of hypereutectic Al-Si alloy has been reported to provide distinct advantages over ingot metallurgy (IM) or rapid solidification/powder metallurgy (RS/PM) process in terms of microstructure refinement. In this study, hypereutectic Al-25Si-2.0Cu-1.0Mg alloy was prepared by OSPREY spray casting process. The change of strain rate sensitivity and Creep transition were analyzed by using the load relaxation test and constant creep test. High temperature deformation behavior of the hypereutectic Al-Si alloy has been investigated by applying the internal variable theory proposed by Chang et al. Especially, the creep resistance of spray casted hypereutectic Al-Si alloy can be enhanced considerably by the accumulation of prestrain.

Net Shaping Process to Minimize Cutting amount of Turbocharger Control Plate (터보차저 컨트롤 플레이트의 절삭량 최소화를 위한 정형공정)

  • Yoon, Pil-Hwan;Lee, Seon-Bong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.4
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    • pp.53-61
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    • 2017
  • Turbocharger is a device for increasing the power of a vehicle engine. The control plate is the main component for fixing the vane of the turbocharger. Now, the control plate is made of austenite steel cutting after the casting process. It has excellent corrosion, heat resistance and mechanical characteristics of material. However, present the process is made by cutting after casting. when cutting is processed after casting, so materials, processing time, and processing energy are lost. Therefore, this study proposes a process to powder compact use of stainless steel Deklak2 and to minimize amount of cutting through net shape process. The mechanical properties of Deklak2 were verified by tensile test, hardness test and relative density measurement, and the governed equation was defined. Also, the curvature radius 1, 2 and the density, affects the shape, were selected as the design parameters, and the best process conditions was proposed through the Taguchi method and the evaluation of SN ratio. And then prototype molds were fabricated and compared with the results of the finite element analysis for the verification, and it was found that the tendency of relative density and dimension was coincided. Therefore, it was found that the amount of cutting can be minimized by only the net shape process after the sintering process and it can be applied to mass production.