• Title/Summary/Keyword: Sintering condition

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Electrochemical Properties of Spinel $LiMn_2O_4$Synthesized at Various Sintering Condition (열처리 조건에 따른 스피넬 $LiMn_2O_4$의 전기 화학적 특성)

  • 한태희;박종광;한병성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.12 no.1
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    • pp.50-55
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    • 1999
  • We have investigated the $LiMn_2O_4$system as an cathode material for lithium rechargeable batteries. $LiMn_2O_4$spinel oxides have been synthesized by a solid state methode. We varied sintering time at a fixed sintering temperature of 75$0^{\circ}C$. In order to investigate the electrochemical properties of prepared $LiMn_2O_4$we assembled three-electrode cells using the working electrode as active material and Li metal as the counter and reference electrodes. The electrolyte was 1 M LiPE$_{6}$-EC:DEC(1:1 by volume). The particle size of sample synthesized at 75$0^{\circ}C$ ranged about 60$\mu m$. The discharge capacity of a cell involving spinel $LiMn_2O_4$ increased with increasing sintering time.e.

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A Study of Sintering Behavior and Crystallization in Li2O-Al2O3-SiO2 (LAS) Glass System by RSM (RSM 법에 의한Li2O-Al2O3-SiO2 (LAS) 유리의 소결 거동과 결정화에 대한 연구)

  • Lee, Kyu-Ho;Kim, Young-Seok;Jung, Young-Joon;Kim, Tae-Ho;Seo, Jin-Ho;Ryu, Bong-Ki
    • Journal of the Korean Ceramic Society
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    • v.44 no.8
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    • pp.451-456
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    • 2007
  • This paper presents results and observations obtained from a study of sintering behavior and crystallization in $Li_2O-Al_2O_3-SiO_2$ (LAS) Glass by screen printing method. The variable experimental conditions were determined carefully by Thermal-Mechanical Analyzer (TMA), Differential Thermal Analyzer (DTA) for setting the optimum transparent sintering conditions in LAS glass system, $10.5Li_2O-14.7Al_2O_3-58.1SiO_2-16.7B_2O_3(wt%)$, such as glass-ceramics which usually have low crystallization temperatures. Crystallization glasses generated during sintering was observed from diffraction patterns by X-Ray Diffraction (XRD), transmittance by UV-Vis spectrometer. Finally, the optimum sintering condition of LAS glass and the relation between factors and results in several sintering conditions were given by using Response Surface Methodology (RSM). From this study, we confirmed that crystallization interrupted densification during glass powder sintering. Furthermore, we observed that main effect of factors in glass powder sintering with concurrent crystallization depended on experimental conditions from main effects plot by MINTAB-14.

Effect of Nozzle Distance and Angle in the Iron-ore Sintering Dual Burner on Flame Characteristics (철광석 소결용 듀얼 버너의 노즐 간격과 각도가 화염 특성에 미치는 영향)

  • Lee, Young-Jun;Hwang, Min-Young;Kim, Gyu-Bo;Song, Ju-Hun;Chang, Young-June;Jeon, Chung-Hwan
    • Journal of Energy Engineering
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    • v.19 no.3
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    • pp.163-170
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    • 2010
  • The objective of this study is to investigate the combustion characteristics of dual type of sintering burner as a function of design parameters using lab-scale sintering burner through experimental and numerical approaches. Combustion characteristics were evaluated by the radical method. The numerical model was verified as a temperature using R type of thermocouple at the bed surface. The effect of nozzle distance and angle were performed through the CFD analysis, and the comparison of burner types. As a results, dual type burner has more wider and uniform flame distribution than single type burner. Asymmetry and 45 degree angle condition have been suggested as an optimal condition for the ignition of the sintering bed surface.

Processing and properties of $Al_{2}O_{3}/SiC$ nanocomposites by polycarbosilane infiltration

  • Jung-Soo Ha;Chang-Sung Lim;Chang-Sam Kim
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.12 no.2
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    • pp.80-86
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    • 2002
  • $Al_{2}O_{3}/SiC$ nanocomposites were made by infiltrating partially sintered alumina bodies with polycarbosilane (PCS) solutions, which is a SiC polymer precursor, with pressureless sintering. The SiC content, densification, phases, strength, and microstructure were investigated with the processing parameters such as PCS solution concentration and heat treatment condition for PCS pyrolysis and sintering. The results were compared with those for pure alumina and nanocomposite samples made by the existing polymer precursor route (i.e. the PCS addition process). The SiC contents of up to 1.5 vol% were obtained by the PCS infiltration. PCS pyrolysis, followed by air heat treatment, was needed before sintering to avoid a cracking problem and to attain a densification as high as 98 % of theoretical. The nanocomposites exhibited significantly higher strength than pure alumina and those prepared by the PCS addition process despite larger grain size. Besides $\alpha-Al_{2}O_{3}/SiC$ and $\beta-SiC$ phases, mullite was present a little in the nanocomposites, which resulted from the reaction of $SiO_{2}$ in the pyrolysis product of PCS with the $Al_{2}O_{3}$ matrix during sintering. The nanocomposites had intagranular particles believed to be SiC, which is a typical feature of $Al_{2}O_{3}/SiC$ nanocomposites.

Fabrication of Barium Oxide Ferrite Magnet-II (바리움 훼라이트 자석의 시작 - II)

  • 백용현
    • 전기의세계
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    • v.21 no.6
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    • pp.17-20
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    • 1972
  • The magnetic properties of Ba-Ferrite ( $M^{+2}$O.nF $e_{2}$ $O_{3}$ is highly improved under the condition of composition ratio n=4.4 when B $i_{2}$ $O_{3}$ is added to Ferrite, the adding amount and sintering temperature which affect the magnetic properties were investigated and the following results; were obtained; 1. Magnetic properties are varied with B $i_{2}$ $O_{3}$ content and singering temperature, and coercive force and residual induction can be improved with B $i_{2}$ $O_{3}$. 2. The optimal content of B $i_{2}$ $O_{3}$ amount is about 4 mol %, 3. Without the addition of B $i_{2}$ $O_{3}$, the optimal sintering temperature is about 1300.deg. C, but when 4 mol % of B $i_{2}$ $O_{3}$ is added, the optimal sintering temperature falls to the range of 900.deg. C to 1100.deg. C and it also improves magnetic properties. 4. Residual induction increases as the singering temperature is raised to 1100.deg. C. Coercive force also increased as the sintering temperature is raised to 1000.deg. C, but it rapidly decreases when sintering temperature goes beyond 1000.deg. C. 5. Only a negligible change may be noticed in the decrease of Curie temperature by the addition of about 4 mol % of B $i_{2}$ $O_{3}$.

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Microstructure and Mechanical Properties of Ti-6Al-4V Alloy Processed by Metal Injection Molding (금속분말 사출성형된 Ti-6Al-4V 합금의 미세조직 및 기계적 물성)

  • Kim, M.J.;Baek, S.H.;Yoon, D.K.;Lee, E.H.;Kim, J.H.;Ko, Y.G.
    • Transactions of Materials Processing
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    • v.29 no.5
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    • pp.251-256
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    • 2020
  • The purpose of this study is to investigate the effect of sintering condition on the microstructure evolution and tensile properties of the Ti-6Al-4V alloy sample processed by metal injection molding (MIM) in terms of the sizes of the alpha morphology and pore found in the matrix. For this purpose, a series of MIM were conducted on this sample at various sintering temperatures ranging from 1173 to 1373 K for three hours followed by furnace cooling, observed by the scanning electron microscopy. The microstructures sintered in this study showed that, with increasing sintering temperature over beta transus temperature, the transformation of the equiaxed alpha into transformed beta was attained while the size of pores would tend to decrease. Thus, the strength remained unchanged significantly in the tension while ductility increased to some extent as sintering temperature increased. Such mechanical behavior would be explained in relation to the microstructure evolution of the Ti-6Al-4V sample via the MIM.

Sintering and Dielectric Properties in Cordierite/Glass Composite for LTCC Application (Cordierite/Glass Composite계 LTCC 소재의 소결 및 유전특성)

  • Hwang, Il-Sun;Yeo, Dong-Hun;Shin, Hyo-Soon;Kim, Jong-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.2
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    • pp.144-150
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    • 2008
  • Recently, there has been growing interest in low loss and low dielectric constant material for LTCC application, as the frequency range for electronic devices increases. This study was designed to evaluate the effect of cordierite filler for low dielectric constant LTCC material. From the previous experiments, two glass compositions of B-Si-Al-Zn-Ba-Ca-O and B-Si-Al-Sr-Ca-O system, were chosen. Each powder of two glass compositions was sintered respectively with commercial cordierite powder in temperature range from $800^{\circ}C\;to\;900^{\circ}C$. Crystalline cordierite and glass peaks were affected only with two factors of composition and sintering temperature among various factors. With the optimized condition of two cordierite/glass compositions, obtained dielectric constant was below 5.5 and quality factor was above 1,000. Closed pore of sintered body was controled by sintering temperature and sintering time. When cordierite/glass composite with ratio of 5.5:4.5 was sintered at $900^{\circ}C$, densification was sufficient with good dielectric characteristics of ${\epsilon}_r<5.1,\;Q{\ge}1,000$. Residual fine closed pores could be reduced with control of sintering temperature and time. 3 point bending strength and chemical durability were evaluated to obtain feasibility for substrate material.

Piezoelectric and Dielectric Properties of Low Temperature Sintering PMN-PZN-PZT Ceramics according to the Milling Time (밀링 시간에 따른 저온소결 PMN-PZN-PZT 세라믹스의 압전 및 유전특성)

  • Yoo, Ju-Hyun;Lee, Il-Ha;Lee, Kab-Soo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.12
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    • pp.1039-1043
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    • 2007
  • In this paper, in order to develop low temperature sintering ceramics for multilayer piezoelectric actuator application, PMN-PZN-PZT ceramics were fabricated using $LiCO_3,\;Bi_2O_3$ and CuO as sintering aids. And also, their piezoelectric and dielectric properties were investigated according to the milling time. All the specimens sintered at $930\;^{\circ}C$ showed tetragonal phases without secondary phases. With increasing milling time, piezoelectric and dielectric characteristic of specimens increased up to 60 hours milling time and then decreased due to the agglomeration of fine particle. Accordingly, it seems that 60 hour is optimum milling condition. At the sintering temperature of $930\;^{\circ}C$ and milling time of 60 hour, density, dielectric constant(${\varepsilon}_r$), electromechanical coupling factor (kp), mechanical quality factor (Qm), piezoelectric d constant showed the optimum value of $7.95\;g/m^3$, 1382, 0.546, 1749, 330 pC/N, respectively for multilayer piezoelectric actuator application.

The effect of heat treatment condition on superconducting property and phase analysis of Bi-2223 tapes (Bi-2223 초전도 선재의 열처리에 따른 초전도 특성 및 상분석)

  • Choi, Jeong-Kyu;Ha, Hong-Soo;Lee, Dong-Hun;Yang, Ju-Saeng;Hwang, Sun-Yuk;Ha, Dong-Woo;Oh, Sang-Soo;Kwon, Yeong-Kil;Lee, Se-Jong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05a
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    • pp.73-76
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    • 2003
  • Phase transformation of Bi-2223 tape during the final heat treatment has been investigated through the various duration time of heat treatment in a specially designed 3-step heat treatment. It was found that the phase assemblage in the sintering was determined by the sintering time and temperature. In this study, sintering time was changed to optimize the Bi-2223 phase assemblage, and acquire high critical current density. High critical current samples with Ic = 85 A and Je = 8.9 kA/$cm^2$ have been measured at 77K and self-field for 55-filament tapes sintered by optimum condition.

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Piezoelectric properties ofPbTi$O_3$ system ceramics for hydrophone (하이드로폰용 PbTi$O_3$계 세라믹스의 압전특)

  • 유주현;홍재일
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.44 no.4
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    • pp.479-482
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    • 1995
  • In this study, to improve sintering condition, anisotropic properties ( $k_{t}$/ $k_{p}$) of electromechanical coupling coefficient and piezoelectric constant $d_{h}$ and $g_{h}$, Mn $O_{2}$ impurity was added to the (P $b_{0.76}$C $a_{0.24}$)[( $Co_{1}$2/ $W_{1}$2/)$_{0.04}$ $Ti_{0.96}$] $O_{3}$ ceramics for application to hydrophone devices. Electromechanical coupling coefficients of the specimen with 1.5 [mol%] Mn $O_{2}$ sintered at 1150.deg. C were $k_{t}$=49% and $k_{p}$ = O, which exibited the highest value in piezoelectric anisotropic properties (kt/kp). Without relations with sintering temperature, the highest value of hydrostatic piezoelectric constant $d_{h}$ & $g_{h}$ were shown at the specimen with 1.5 [mol%] Mn $O_{2}$. Accordingly, the best addition amount of Mn $O_{2}$ was 1.5 [mol%] and proper sintering temperature was 1150.deg. C. Hydrostatic piezoelectric constant values of $d_{h}$=64.52[10$^{-12}$ C/N], $g_{h}$=35.92[10$^{-3}$ Vm/N] in the above condition were effectiely extended for hydrophone applications.pplications.ons.

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