• Title/Summary/Keyword: Sintering effect

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The Effect of Ball Milling and Sintering Temperatures on the Sintering Behaviors and Mechanical Properties of $Al_2O_3/SiC$ Nanocomposites ($Al_2O_3/SiC$ 나노복합체의 상압소결 및 역학적 특성에 미치는 볼밀분쇄와 소결온도의 영향)

  • 류정호;나석호;이재형;조성재
    • Journal of the Korean Ceramic Society
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    • v.34 no.6
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    • pp.668-676
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    • 1997
  • Al2O3/SiC nanocomposites are fabricated through intensive ball milling to mix fine SiC particles uniformly with the Al2O3 powder. Another role of milling is to reduce particle sizes by crushing particles as well as agglomerates. However, balls are worn during ball milling and the sample powder mixtures pick up to weight loss of the balls. In this study, pressureless sintering was performed to obtain Al2O3/SiC nanocomposites. It was found that the wear rate of zirconia balls during milling was considerable, and the zirconia addition after even a few hours of ball milling could increase the sintering rates of the nanocomposites significantly. Thus, addition of ZrO2 changed the sintering behaviors as well as mechanical properties of Al2O3/SiC nanocomposites.

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Influence of High-energy Milling and Sintering Cycle on Obtaining of TiAl from Elemental Ti and Al Powders

  • Esteban, P.G.;Gordo, E.;Ruiz-Navas, E.M.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.727-728
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    • 2006
  • The present work studies the influence of high-energy milling (HEM) and sintering cycle of Ti and Al powders on the obtainment of TiAl. This study shows that HEM modifies the diffusion processes during the sintering stage. The samples were obtained by cold uniaxial and isostatic pressing, pre-sintered at different temperatures, and heated up to the sintering temperature. This study also shows the effect of powder additions processed by HEM on the sintering behavior of elemental Ti and Al powders.

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Effect of Debinding and Sintering Conditions on the Tensile Properties of Water-atomized STS 316 L Parts by Powder Injection Molding (수분무 STS 316L 분말사출성형체의 탈지 및 소결공정에 따른 인장 특성)

  • 윤태식;성환진;안상호;이종수
    • Journal of Powder Materials
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    • v.9 no.4
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    • pp.218-226
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    • 2002
  • The purpose of the present study is to investigate the influence of thermal debinding and sintering conditions on the sintering behavior and mechanical properties of PIMed 316L stainless steel. The water atomized powders were mixed with multi-component wax-base binder system, injection molded into flat tensile specimens. Binder was removed by solvent immersion method followed by thermal debinding, which was carried out in air and hydrogen atmospheres. Sintering was done in hydrogen for 1 hour at temperatures ranging from 1000℃ to 1350℃ The weight loss, residual carbon and oxygen contents were monitored at each stage of debinding and sintering processes. Tensile properties of the sintered specimen varied depending on the densification and the characteristics of the grain boundaries, which includes the pore morphology and residual oxides at the boundaries. The sinter density, tensile strength (UTS), and elongation to fracture of the optimized specimen were 95%, 540 MPa, and 53%, respectively.

Co-sintering of M2/316L Layers for Fabrication of Graded Composite Structures

  • Firouzdor, V.;Simchi, A.;Kokabi, A.H.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.696-697
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    • 2006
  • This paper presents the densification and microstructure evolution of bilayer components made from 316L stainless steel and M2 High speed steel during co-sintering process. The sintering was carried out at temperatures ranging from $1230-1320^{\circ}C$ in a reducing atmosphere. The addition of boron to 316L was examined in order to increase the densification rate and improve the sintering compatibility between the two layers. It was shown that the mismatch strain bettwen the two layers induces biaxial stresses during sintering, influencing the densification rate. The effect of boron addition was also found to be positive as it improves the bonding between the two layers.

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Development of $Al_2O_3-Ni$ FGMs Produced by Spark Plasma Sintering

  • Casari, Francesco;Zadra, Mario;Girardini, Luca;Molinari, Alberto
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.87-88
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    • 2006
  • Ceramic-Metal Functionally Graded Materials (FGM) are of great interest for application as Thermal Barrier Coating (TBC) or Wear Resistant Coating (WRC). Spark Plasma Sintering (SPS) is a promising techniques for time-saving consolidation of laminated/graduated powder systems: SPS is a pressure-assisted electrical sintering method which directly applies a pulsed DC current as heat source. In the present work, production of $Al_2O_3-Ni$ FGMs by means of Spark Plasma Sintering is considered; effect of sintering condition on density, hardness and fracture toughness is studied. Problems correlated to this new processing technology are discussed.

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Improved sintering process of counter electrode for dye-sensitized solar cells

  • Lee, Su Young;Kim, Sang Ho
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2012.05a
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    • pp.227-228
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    • 2012
  • In interfaces between carbon black or Pt and FTO glass in dye-sensitized solar cell counter electrodes, a marginal resistant channel for electrons, we tried to improve the connection by modifying the sintering process. A stepwise sintering process for carbon black and Pt counter electrodes was applied and its effect on power conversion efficiency was studied. Power conversion efficiencies of built-in DSSC made by a one-step sintering process with carbon black and Pt counter electrodes were about 5.01% and 5.02%, respectively. Cells made with the stepwise sintering process were 5.96% and 6.21%, respectively, indicating an 20% improvement. Fill factor (FF) increased, and it was them main reason for the power conversion efficiency improvement. Step wise sintering increased the adhesion of the interface and reduced the film thickness and surface roughness. As a result, the resistivity of the counter electrode and EIS impedance of DSSCs decreased.

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