검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 72

        21.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we report the sintering behavior and properties of a Ge2Sb2Te5 alloy powders for use as asputtering target by spark plasma sintering. The effect of various sintering parameters, such as pressure, temperature andtime, on the density and hardness of the target has been investigated in detail. Structural characterization was performedby scanning electron microscopy and X-ray diffraction. Hardness and thermal properties were measured by differentialscanning calorimetry and micro-vickers hardness tester. The density and hardness of the sintered Ge2Sb2Te5 materialswere 5.8976~6.3687 g/cm3 and 32~75 Hv, respectively.
        4,000원
        22.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A bulk metallic glass-forming alloy, metallic glass powders was used for good commercial availability and good formability in supercooled liquid region. In this study, the Ni-based metallic glass was synthesized using by high pressure gas atomized metallic glass powders. In order to create a bulk metallic glass sample, the metallic glass powders with ball-milled Ni-based amorphous powder with 40%vol brass powder and Cu powder for 20 hours. The composite specimens were prepared by Spark Plasma Sintering for the precursor. The SPS was performed at supercooled liquid region of Ni-based metallic glass. The amorphous structure of the final sample was characterized by SEM, X-ray diffraction and DSC analysis.
        3,000원
        23.
        2012.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study was focused on the analysis of the electric and thermal properties of spark plasma sintered thermoelectric material. The crystal structure, microstructure, electric and thermal properties of the sintered body were evaluated by measuring XRD, SEM, electric resistivity, Hall effect and thermal conductivity. The sintered body showed anisotropic crystal structure. The c-axis of the crystal aligned in a parallel direction with applied pressure during spark plasma sintering. The degree of the crystal alignment increased with increasing sintering temperature and sintering time. The electric resistivity and thermal conductivity of the sintered body showed anisotropic characteristics result from crystal alignment.
        4,000원
        24.
        2012.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Bismuth antimony telluride (BiSbTe) thermoelectric materials were successfully prepared by a spark plasma sintering process. Crystalline BiSbTe ingots were crushed into small pieces and then attrition milled into fine powders of about 300 nm ~ 2μm size under argon gas. Spark plasma sintering was applied on the BiSbTe powders at 240, 320, and 380˚C, respectively, under a pressure of 40 MPa in vacuum. The heating rate was 50˚C/min and the holding time at the sintering temperature was 10 min. At all sintering temperatures, high density bulk BiSbTe was successfully obtained. The XRD patterns verify that all samples were well matched with the Bi0.5Sb1.5Te3. Seebeck coefficient (S), electric conductivity (σ) and thermal conductivity (k) were evaluated in a temperature range of 25~300˚C. The thermoelectric properties of BiSbTe were evaluated by the thermoelectric figure of merit, ZT (ZT = S2σT/k). The grain size and electric conductivity of sintered BiSbTe increased as the sintering temperature increased but the thermal conductivity was similar at all sintering temperatures. Grain growth reduced the carrier concentration, because grain growth reduced the grain boundaries, which serve as acceptors. Meanwhile, the carrier mobility was greatly increased and the electric conductivity was also improved. Consequentially, the grains grew with increasing sintering temperature and the figure of merit was improved.
        4,000원
        25.
        2012.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Magnetic properties and the microstructures of magnets prepared by spark plasma sintering were investigated in order to enhance magnetic properties by grain size control. Nd-Fe-B magnets were fabricated by the spark plasma sintering under 30 MPa at various temperatures. The grain size was effectively controlled by the spark plasma sintering and it was possible to make Nd-Fe-B magnets with grain size of 5.9 .
        4,000원
        26.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The p-type thermoelectric compounds of based doped with 3wt% Te were fabricated by a combination of rapid solidification and spark plasma sintering (SPS) process. The effect of holding time during spark plasma sintering (SPS) on the microstructure and thermoelectric properties were investigated using scanning electron microscope (SEM), X-ray diffraction (XRD) and thermoelectric properties. The powders as solidified consisted of homogeneous thermoelectric phases. The thermoelectric figure of merit measured to be maximum () at the SPS temperature of .
        4,000원
        27.
        2008.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        SOFC (Solid Oxide Fuel Cell) Ni-YSZ anode was fabricated by the spark plasma sintering (SPS) process and its microstructure and electrical properties were investigated in this study. The spark plasma sintering process was carried out at for holding time of 5 min under 40 MPa. To fabricate Ni-YSZ anode, the SPS processed specimens were reduced at under atmosphere. The reduced specimens showed relative density of according to sintering temperature. And also, the electrical conductivity of reduced specimens after sintering at 900 and showed (S/cm) values at the measuring range of .
        4,000원
        28.
        2008.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper deals with the phase analysis of bulk using spark plasma sintering process after ball milling. Mg and amorphous B powders were used as raw materials, and milled by planetary-mill for 9 hours at argon atmosphere. In order to confirm formation of phase, DTA and XRD were used. The milled powders were fabricated to bulk at the various temperatures by Spark Plasma Sintering. The fabricated bulk was evaluated with XRD, EDS, FE-SEM and PPMS. In the DTA result, reaction on formation of phase started at . This means that ball milling process improves reactivity on formation of phase. The MgO and FeB phases were characterized from XRD result. MgO and FeB were undesirable phases which affect formation of phase, and it's distribution could be confirmed from EDS mapping result. Spark Plasma Sintered sample for 5 min at was relatively densified and it's density and transition temperature showing super conducting property were and 21K.
        4,000원
        29.
        2008.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fe based () amorphous powder were produced by a gas atomization process, and then ductile Cu powder fabricated by the electric explosion of wire(EEW) were mixed in the liquid (methanol) consecutively. The Fe-based amorphous - nanometallic Cu composite powders were compacted by a spark plasma sintering (SPS) processes. The nano-sized Cu powders of 200 produced by EEW in the methanol were mixed and well coated with the atomized Fe amorphous powders through the simple drying process on the hot plate. The relative density of the compacts obtained by the SPS showed over 98% and its hardness was also found to reach over 1100 Hv.
        4,000원
        30.
        2008.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Microstructure and mechanical properties of WC-3wt% Co cemented carbides, fabricated by a sparkplasma sintering (SPS) process, were investigated in this study. The WC-3wt%Co powders were sintered at900~1100oC for 5min under 40MPa in high vacuum. The density and hardness were increased as the sinteringtemperature increased. WC-3wt%Co compacts with a relative density of 97.1% were successfully fabricated at1100oC. The fracture toughness and hardness of a compact sintered at 1100oC were 21.6MPa·m1/2 and4279Hv, respectively.
        4,000원
        31.
        2008.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        ZnS- composite is normally used for sputtering target. In recent years, high sputtering power for higher deposition rate often causes crack formation of the target. Therefore the target material is required that the sintered target material should have high crack resistance, excellent strength and a homogeneous microstructure with high sintered density. In this study, raw ZnS and ZnS- powders prepared by a 3-D mixer or high energy ball-milling were successfully densified by spark plasma sintering, the effective densification method of hard-to-sinter materials in a short time. After sintering, the fracture toughness was measured by the indentation fracture (IF) method. Due to the effect of crack deflection by the residual stress occurred by the second phase of fine , the hardness and fracture toughness reached to 3.031 GPa and , respectively
        4,000원
        32.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Cu-based bulk metallic glass (BMG) composites containing Zr-based metallic glass phase have been consolidated by spark plasma sintering using the mixture of Cu-based and Zr-based metallic glass powders in their overlapped supercooled liquid region. The Zr-based metallic glass phases are well distributed homogeneously in the Cu-based metallic glass matrix after consolidation process. The successful consolidation of BMG composites with dual amorphous phases was corresponding to the sound viscous flow of the two kinds of metallic glass powders in their overlapped supercooled liquid region.
        4,000원
        34.
        2007.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The fabrication of Fe alloy-40 wt.%TiC composite materials using spark plasma sintering process after ball-milling was studied. Raw powders to fabricate Fe alloy-TiC composite were Fe alloy, and activated carbon. Fe alloy powder was Distaloy AE (4%Ni-1%Cu-0.5%Mo-0.01%C-bal.%Fe) made by Hoeganes company with better toughness and lower melting point. These powders were ball-milled in horizontal attrition ball mill at a ball-to-powder weight ratio of 30 : 1. After that, these mixture powders were sintered by using spark plasma sintering apparatus for 5 min at in vacuum atmosphere under torr. DistaloyAE-40 wt.%TiC composite was directly synthesized by dehydrogenation and carburization reaction during sintering process. The phase transformation of as-milled powders and sintered materials was confirmed using X-ray diffraction (XRD) and transmission electron microscope (TEM). The density and harness materials was measured in order to confirm the densification behavior. In case of DistaloyAE-40 wt.%TiC composite retained for 5 min at , it has the relative density of about 96% through the influence of rapid densification and fine TiC particle reinforced Fe-based composites materials.
        4,000원
        37.
        2007.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bulk metallic glass (BMG) composite was fabricated by consolidation of milled metallic glass composite powders. The metallic glass composite powder was synthesized by a controlled milling process using the Cu-based metallic glass powder blended with 30 vol% Zr-based metallic glass powders. The milled composite powders showed a layered structure with three metallic phases, which is formed as a result of mechanical milling. By spark plasma sintering of milled metallic glass powders in the supercooled liquid region, a fully dense BMG composite was successfully synthesized.
        4,000원
        40.
        2006.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ni based() bulk metallic glass(BMG) powders were produced by a gas atomization process, and ductile Cu powders were mixed using a spray drying process. The Ni-based amorphous powder and Cu mixed Ni composite powders were compacted by a spark plasma sintering (SPS) processes into cylindrical shape. The relative density varied with the used SPS mold materials such as graphite, hardened steel and WC-Co hard metal. The relative density increased from 87% to 98% when the sintering temperature increased up to in the WC-Co hard metal mold.
        4,000원
        1 2 3 4