• Title/Summary/Keyword: SHS(Self-propagating High-temperature Synthesis)

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Characterization of TiC/Mg Composites Fabricated by in-situ Self-propagating High-temperature Synthesis followed by Stir Casting Process (자전연소합성법 및 교반주조 공정으로 제조된 TiC/Mg 금속복합재료의 특성연구)

  • Lee, Eunkyung;Jo, Ilguk
    • Composites Research
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    • v.33 no.5
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    • pp.256-261
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    • 2020
  • In this study, the ignition temperature of the Al-Ti-C reaction system, the microstructure and the mechanical properties of the TiC/Mg composite which produced by the self-propagating high-temperature synthesis (SHS) followed by stir casting process were investigated. Mg based composite with uniformly dispersed 0, 10, 20, and 30 vol.% TiC were fabricated, and higher volume fraction of TiC reinforced composite showed superior compressive strength and wear resistance as compared with Mg matrix. It is attributed to the less contamination, defects, impurities in TiC/Mg composite by the in-situ SHS yield effective load transfer from the matrix to the reinforcement.

Synthesis of $TiB_2-Al_2O_3$ Composite by Self-Propagating High Temperature Synthesis (SHS) and Its Pressureless Sintering (SHS법에 의한 $TiB_2-Al_2O_3$계 복합물의 합성 및 상압소결에 관한 연구)

  • 최상욱;조동수;김세용;남건태
    • Journal of the Korean Ceramic Society
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    • v.31 no.5
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    • pp.552-560
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    • 1994
  • A composite of TiB2-Al2O3 system was successfully prepared from a mixture of TiO2, B2O3, and Al by self-propagating high temperature synthesis (SHS) with a novel characteristic, utilizing the internal oxidation heat of aluminium metal of the mixture, instead of by a conventional technique, externally heating a mixture of Ti, B and Al2O3. From a mixture with B/Ti molar ratio of =2.0, pure two phases of TiB2 and $\alpha$-Al2O3 with good crystallinity and small, uniform sizes were formed. However, when the B/Ti molar ratio of the mixture goes to a value less than 2.0, in addition to the above main minerals, a small smounts of metastable phases such as TiB and Ti3B4 were formed. It was found that about 60%, the optimum green density of compacts gave their highest reaction rate and temperature during SHS process. TiB2-Al2O3 system composite with B/Ti molar ratio of =2.0 could be pressurelessly sintered even at 190$0^{\circ}C$ under Ar gas flows without any addition of sintering aids, showing their good properties such as 91.2% in relative density, 2750 kgf/$\textrm{mm}^2$ in Vickers hardness and 2620 kgf/$\textrm{cm}^2$ in flexural strength.

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Study on Synthesis and Sintering Characterization of Ti-Si System Ceramics by Self-Propagating High Temperature Synthesis (SHS법에 의한 Ti-Si계 세라믹스의 합성 및 소결체의 특성에 관한 연구)

  • Kim, Do-Kyung;Park, Sung;Cho, Duk-Ho;Cho, Kurn;Lee, Hyung-Bock
    • Journal of the Korean Ceramic Society
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    • v.31 no.3
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    • pp.265-274
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    • 1994
  • Intermetallic Ti-Si system ceramics were synthesized from stochiometric mixtures of titanium and silicone powders in vacuum by Self-propagating High-temperature Synthesis(SHS). In each cases of Ti5Si3, Ti5Si4 and TiSi, and TiSi2 synthesis, 20wt% product dilution, direct ignition and SHS chemical furnace method were employed. The combustion modes, which were observed during the synthesis process by using the high speed camera, of Ti5Si3, Ti5Si4, TiSi, and TiSi2 exhibit spin, osciallatory, steady-state, and spin combustion, respectively. With increasing Ti/Si molar ratio an decrease of combustion velocities was found. From the results on the measurement of the flexural strength, the specimen hot pressed at 135$0^{\circ}C$ for 30 min using synthesized Ti5Si4 powders showed the highest flexural strength at 215 MPa.

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Study on Synthesis and Mechanical Properties of (B.Si)C Composite by Self Propagating High Temperature Synthesis Chemical Furnace (SHS 화학로에 의한 (B.Si)C 복합체의 합성 및 기계적 특성에 관한 연구)

  • 이형복;조덕호;이재원
    • Journal of the Korean Ceramic Society
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    • v.32 no.4
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    • pp.413-418
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    • 1995
  • The (B.Si)C composite was prepared form the mixture of metal boron, silicon, and carbon powders in Ar atmosphere by Self-propagating High-temperature Synthesis Chemical Furnace. The characterization of synthesized power and sintered body were investigated. The microstructure of sintered body suggested that SiC boundary was made between B4C grains. The most excellent mechanical properties, the relative density of 95% oftheoretical value, 3 point flexural strength of 360MPa, and fracture toughness of 3.6MN/m3/2 could be obtained in 80wt% B4C-20 wt% SiC composite were obtained.

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BSCCO Superconducting Powder by SHS

  • Soh, Dea-Wha;Cho, Yong-Joon;Korobova, N.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.99-102
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    • 2002
  • The BSCCO superconductor materials of using Self-propagating High-temperature Synthesis (SHS) were studied. Mechano-chemical activation - as a pre-treatment of the reactants mixture - strongly influences the kinetic parameters, the reaction mechanism, and the composition and structure of the final product. In this paper as an effort for fabricating the SHSed BSCCO superconductor powder SHS method was considered to application in the synthesis of superconducting materials.

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Effect of Zn and Mn on the Synthesis of Zn2SiO4:Mn2+ Phosphor by SHS (자전연소 합성법을 이용한 Zn2SiO4:Mn2+ 형광체 합성시 Zn 및 Mn의 영향)

  • Lee Jong Eun;Kim Byeong Beom;Lee Hyeok Hui;Won Chang Whan
    • Korean Journal of Materials Research
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    • v.14 no.12
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    • pp.889-892
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    • 2004
  • The synthesis of $Zn_{2}SiO_4:Mn^{2+}$ for PDP green phosphor by SHS(Self-propagating High temperature Synthesis method) was studied. The precursors were well mixed and cold compacted. And then, the green pellet was synthesized at high temperature through self-propagating high temperature zone. Because this reaction uses the heat resulted from the oxidation of Zn metal powder in this system, Zn/ZnO mole ratio is one of the most important reaction variable. Throughout several experiments, the optimal condition of Zn/ZnO mole ratio and Mn concentration are 1.2/0.8 and 0.05mo1e, respectively.

SHS of Oxide Systems Based on MCR of Quartz Modified by Organometallic Compounds

  • Soh, Dea-Wha;Tlek, Ketegenov;Z.A., Mansurov
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.666-669
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    • 2002
  • The differences of the effects of mechanical substance pre-activation in the mills with divers force effect schemes on the self-propagating high temperature synthesis (SHS) of the $SiO_2$ + 37.5% Al system were investigated. The power saturation of activated material state are estimated referring on the variations of dilatometry curve paths. The effects of activation time on the temperature of sample self-ignited in the furnace, combustion temperature and completeness of the quartz reaction with aluminium were determined. The enhancing effects of organic modifiers of quartz particle surfaces on the further SHS synthesis development were shown.

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A Study on the Synthesis of Titanium Hydride by SHS(Self-propagating High-temperature Synthesis) Method and the Preparation of Titanium Powder (SHS법에 의한 티타늄 수소화물 합성 및 티타늄 분말 제조에 관한 연구)

  • Ha, Ho;Park, Seung-Soo;Lee, Hee-Cheol
    • Applied Chemistry for Engineering
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    • v.5 no.2
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    • pp.263-273
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    • 1994
  • Titanium powder prepared by dehydrogenating the titanium hydride which is synthesized by reacting Ti-sponge (99.67%) with hydrogen using the self-propagating high-temperature synthesis method. In the synthesis of titanium hydride, the particle size of the product was found dependent on the amount of hydrogen incorporated into the titanium such that the particle size of titanium hydride decreased with increasing hydrogen pressure and after-burn time. In the dehydrogenation process, as the dehydrogenation time increase, the particle size of titanium powder increased due to partial melting and sintering of titanium particles.

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