• Title/Summary/Keyword: MoSi$_2$ Powder

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Fabrication of $MoSi_2$-TiC Composite Powders by Mechanical Alloying (기계적 압금화에 의한 $MoSi_2$-TiC 복합분말의 제조)

  • 윤종열
    • Journal of Powder Materials
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    • v.6 no.2
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    • pp.178-185
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    • 1999
  • MoSi$_2$-TiC composite powders were fabricated by in-situ reaction through mechanical alloying. Also the monolithic MoSi$_2$ as well as TiC were synthesiced by mechanical alloying for comparison. An abrupt increase of vial surface temperature was detected due to a sudden reaction between elemental powders during milling. The reaction time for synthesis of composite powders decreased with increasing the content of (Ti+C) powder. It was found that a significant decrease of Ti grain size was observed with increasing the milling time. And the synthesis reaction of MoSi$_2$-TiC composite powders were largely dependent on the reaction between Ti and C powders.

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Interfacial Moderation and Characterization of Nb/MoSi2 Bonding Materials (Nb/MoSi2 접합재료의 계면 수정 및 특성)

  • Lee, Sang-Pill;Yoon, Han-Ki
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.7
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    • pp.1132-1137
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    • 2003
  • This study dealt with the suppression of interfacial reaction between Nb and MoSi$_2$ for the fabrication of high toughness Nb/MoSi$_2$ laminate composites, based on the results of a thermodynamical estimation. Especially, the effect of ZrO$_2$ particle on the interfacial reaction of Nb/MoSi$_2$ bonding materials has been examined. Nb/MoSi$_2$ bonding materials have been successfully fabricated by alternatively stacking matrix mixtures and Nb sheets and hot pressing in the graphite mould. The addition of ZrO$_2$ particle to MoSi$_2$ matrix is obviously effective for promoting both the interfacial reaction suppression and the sintered density of Nb/MoSi$_2$ bonding materials, since it is caused by the formation of ZrSiO$_4$ in the MoSi$_2$-ZrO$_2$ matrix mixture. The interfacial shear strength of Nb/MoSi$_2$ bonding materials also decreases with the reduction of interfacial reaction layer associated with the content of ZrO$_2$ particle and the fabrication temperature.

Research Trends of the Mo-Si-B Alloys as Next Generation Ultra-high-temperature Alloys (차세대 초고온 합금인 Mo-Si-B 합금의 연구 동향)

  • Choi, Won June;Park, Chun Woong;Park, Jung Hyo;Kim, Young Do;Byun, Jong Min
    • Journal of Powder Materials
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    • v.26 no.2
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    • pp.156-165
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    • 2019
  • Over the last decade, the next generation's ultra-high-temperature materials as an alternative to Nickel-based superalloys have been highlighted. Ultra-high-temperature materials based on refractory metals are one of several potential candidates. In particular, molybdenum alloys with small amounts of silicon and boron (Mo-Si-B alloys) have superior properties at high temperature. However, research related to Mo-Si-B alloys were mainly conducted by several developed countries but garnered little interest in Korea. Therefore, in this review paper, we introduce the development history of Mo-Si-B alloys briefly and discuss the properties, particularly the mechanical and oxidation properties of Mo-Si-B alloys. We also introduce the latest research trends of Mo-Si-B alloys based on the research paper. Finally, for domestic research related to this field, we explain why Mo-Si-B alloys should be developed and suggest the potential directions for Mo-Si-B alloys research.

Neutron Diffraction Analysis of Tungsten-Molybdenum-Disilicide Powders Formed by Self-propagating High Temperature Synthesis

  • Choi, Y.;Kim, Y.S.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1325-1326
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    • 2006
  • Tungsten-molydiside $W_xMo_{1-x}Si_2$ was synthesized by self-propagating high temperature synthesis (SHS). The SHS product with the initial composition of (0.5Mo+0.5W+2Si) contains 23.9% $MoSi_2$, 40.89% $WSi_2$ with remaining 9.11% Mo, 9.16% Si and 16.94%W. Lattice parameters of the $MoSi_2$ and $WSi_2$ determined by Rietvelt analysis were a=0.3206 nm, c=0.7841 nm and a=0.3212 nm, c=0.7822 nm, respectively.

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