• Title/Summary/Keyword: Sintered Powder

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Thermoelectric Property of Ball Milled Bi-Te-Sb Powder (볼밀링한 Bi-Te-Sb계 분말의 열전특성에 관한 연구)

  • Yu Ji-Hun;Bae Seung-Chul;Ha Gook-Hyun;Kim Byoung-Kee;Lee Gil-Gun
    • Journal of Powder Materials
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    • v.12 no.6 s.53
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    • pp.387-392
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    • 2005

  • The p-type semiconductor $Bi_2Te_3-Sb_2Te_3$ thermoelectric materials were fabricated by melting, milling and sintering process and their thermoelectric properties were characterized. The compound materials were ball-milled with milling time and the powders were sintered by spark plasma sintering process. The ball milled powders had equiaxial shape and approedmately $1\~3{\mu}m$ in size. The figure of meritz of sintered thermoelectric materials decreased with milling time because of lowered electrical resistivity. The thermoelectric properties of $Bi_2Te_3-Sb_2Te_3$ materials have been discussed in terms of electrical property with ball mill process.

  • https://doi.org/10.4150/KPMI.2005.12.6.387 인용 PDF KSCI

Ammonium uranate hydrate wet reconversion process for the production of nuclear-grade UO2 powder from uranyl nitrate hexahydrate solution

  • Byungkuk Lee ;Seungchul Yang;Dongyong Kwak ;Hyunkwang Jo ;Youngwoo Lee;Youngmoon Bae ;Jayhyung Lee
    • Nuclear Engineering and Technology
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    • v.55 no.6
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    • pp.2206-2214
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    • 2023

  • The existing wet reconversion processes for the recovery of scraps generated in manufacturing of nuclear fuel are complex and require several unit operation steps. In this study, it is attempted to simplify the recovery process of high-quality fuel-grade UO2 powder. A novel wet reconversion process for uranyl nitrate hexahydrate solution is suggested by using a newly developed pulsed fluidized bed reactor, and the resultant chemical characteristics are evaluated for the intermediate ammonium uranate hydrate product and subsequently converted UO2 powder, as well as the compliance with nuclear fuel specifications and advantages over existing wet processes. The UO2 powder obtained by the suggested process improved fuel pellet properties compared to those derived from the existing wet conversion processes. Powder performance tests revealed that the produced UO2 powder satisfies all specifications required for fuel pellets, including the sintered density, increase in re-sintered density, and grain size. Therefore, the processes described herein can aid realizing a simplified manufacturing process for nuclear-grade UO2 powders that can be used for nuclear power generation.

  • https://doi.org/10.1016/j.net.2023.02.019 인용 PDF