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        검색결과 3

        1.
        2005.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ultrafine copper powder was prepared from slurry with hydrazine, a reductant, under . The influence of various reaction parameters such as temperature, reaction time, molar ratio of , PvP and NaOH to Cu in aqueous solution had been studied on the morphology and powder phase of Cu powders obtained. The production ratio of Cu from CuO was increased with the ratio of and the temperature. When the ratio of was higher than 2.5 and the temperature was higher than , CuO was completely reduced into Cu within 40 min. The crystalline size of Cu obtained became fine as the temperature increase, whereas the aggregation degree of particles was increased with the reaction time. The morphology of Cu powder depended on that of the precursor of CuO and processing conditions. The average particle size was about
        4,000원
        2.
        2004.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study for preparation of aluminum nitride (AlN) with high purity was carried out by self-propagating high-temperature synthesis method in two different systems, Al-N and Al-N-AlN, with the change of nitrogen gas pressure and dilution factor. On the occasion of Al-N system, unreacted aluminum was detected in the product in spite of high nitrogen pressure, 10 MPa, This may be caused by obstructing nitrogen gas flow to inner part of molten and agglomerate of aluminum, formed in pre-heating zone. In Al-N-AlN system, AlN with a purity of 95% or ever can be prepared in the condition of f 0.5, PN2 1 MPa, and the purity can be elevated to 98% over in the condition of f = 0.7 and PN2 = 10 MPa
        4,000원
        3.
        2004.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ni-diamond composite powders with nickel layer of round-top type on the surface of synthetic diamond (140/170 mesh) were prepared by the electroless plating method (EN) with semi-batch reactor. The effects of nickel concentration, feeding rates of reductant, temperature, reaction time and stirring speeds on the weight percentage and morphology of deposited Ni, mean particle size and specific surface area of the composite powders were investigated by Atomic Adsortion Spectrometer, SEM-EDX, PSA and BET. It was found that nucleated Ni-P islands, acted as catalytic sites for further deposition and grown into these relatively thick layers with nodule-type on the surface of diamond by a lateral growth mechanism. The weight percentage of Ni in the composite powder increased with reaction time, feeding rate of reductant and temperature, but decreased with stirring speed. The weight percentage of Ni in Ni-diamond composite powder was 55% at 150 min., 200 rpm and 7 .
        4,000원