• 한국초전도학회:학술대회논문집
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• v.10
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• pp.293-297
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• 2000

Multiseeding with (100)/(100) grain junctions of top-seeded melt growth (TSMG) processed YBCO superconductors was studied. The effect of the number of seeds and the distance between two seeds on the levitation forces and the trapped magnetic fields of the TSMG-processed YBCO samples was investigated. Multiple seeding shortened the processing time for the fabrication of TSMC-processed YBCO superconductors. The large magnetic field was trapped at the grain junction when two seeds was placed without spacing, while the amount of the magnetic field decreased when the seed distance increased. This is attributed to the increased amount of the residual melt phases around the grain junctions.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2001.02a
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• pp.139-141
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• 2001

YBCO superconductors were prepared by top-seeded melt growth process using various numbers of seeds. The levitation forces and trapped magnetic fields of the top surfaces of the samples were measured using Nd-B-Fe permanent magnets It was found that the processing time was greatly reduced by multiple seeding, but the properties were decreased as the number of seeds was increased. The degradation of the properties is attributed to the presence of the nonsuperconducting phases at the grain boundaries as result of the entrapment of a residual melt at grain boundaries during melt processing.

• Journal of the Korean Ceramic Society
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• v.31 no.4
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• pp.399-406
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• 1994

The SiC/MoSi2 composite material was prepared by infiltration with the mixture of metal Si and MoSi2 into the preform of $\alpha$-SiC and graphite under the vacuum atmosphere of 10-1 torr. The mechanical properties, phases and microstructural characteristics have been investigated by employing an universal testing machine, scanning electron microscope and X-ray diffractometer. With the increase of MoSi2/Si mixing content, the quantity of the residual silicon phase was decreased and the hardness and fracture toughness of composite materials were increased. Also, as the infiltration temperature increased, a lot of fine-grained $\beta$-SiC phases, which were produced from the reaction of graphite and liquid silicon melt, were transformed to $\alpha$-SiC phases.