검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 13

        5.
        2006.09 구독 인증기관·개인회원 무료
        The microstructure of the extruded Al-20Si bars showed a homogeneous distribution of eutectic Si and primary Si particles embedded in the Al matrix. The grain size of α-Al varied from 150 to 600 nm and the size of the eutectic Si and primary Si in the extruded bars was about 100 - 200 nm. The room temperature tensile strength of the alloy with a powder size <26μm was 322 MPa, while for the coarser powder (45-106μm) it was 230 MPa. With decreasing powder size from 45-106μm to <26μm, the specific wear of all the alloys decreased significantly at all sliding speeds due to the higher strength achieved by ultrafine-grained constituent phases. The fracture mechanism of failure in tension testing and wear testing was also studied.
        6.
        2006.09 구독 인증기관·개인회원 무료
        This research reports for the successful consolidation of Al2O3 powder with retained ultra-fine structure using MPC and sintering. Measurements in the consolidated Al2O3 bulk indicated that hardness, fracture toughenss, and breakdown voltage have been much improved relative to the conventional polycrystalline materials. Finally, optimization of the compaction parameters and sintering conditions will lead to the consolidation of Al2O3 nanopowder with higher density and even further enhanced mechanical properties.
        7.
        2006.04 구독 인증기관·개인회원 무료
        The n-type compound was newly fabricated by gas atomization and hot extrusion, which is considered to be a mass production technique of this alloy. The effect of powder size on thermoelectric properties of 0.04% doped alloy were investigated. Seebeck coefficient and Electrical resistivity increased with increasing powder size due to the decrease in carrier concentration by oxygen content. With increasing powder size, the compressive strength of alloy was increased due to the relative high density. The compound with size shows the highest power factor among the four different powder sizes. The rapidly solidified and hot extruded compound using powder size shows the highest compressive strength.
        8.
        2006.04 구독 인증기관·개인회원 무료
        Several titanate powders (, etc.) were synthesized by an ethylene glycol solution route. Titanium isopropoxide and nitrate salts were dissolved in stoichiometric proportions in liquid-type ethylene glycol without any precipitation. The parent precursor sols were dried to porous gels, and then the gels were calcined and crystallized. All synthesized titanate powders had stable crystallization behavior at low temperature and high specific surface area after a simple ball-milling process. A three-component PZT powder was also synthesized successfully by the ethylene glycol method. In this study, the characteristics of the multi-component titanate powders by the ethylene glycol method are examined.
        9.
        2006.04 구독 인증기관·개인회원 무료
        Pure and stable YAG powders were synthesized by a PVA (polyvinyl alcohol) polymer solution technique. PVA was used as an organic carrier for the precursor ceramic gel. The precursor gels were crystallized to YAG at relatively a low temperature of . The synthesized powders, which have nano-sized primary particles, were soft and porous, and the porous powders were ground to sub-micron size by a simple ball milling process. The ball-milled powders were densified to 94% relative density at for 1h. In this study, the characteristics of the synthesized YAG powders were examined.
        13.
        1981.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        6,600원