간행물
한국분말야금학회 학술대회논문집
- 발행기관 한국분말재료학회(구 한국분말야금학회)
- 자료유형 학술대회
- 간기 부정기
- 수록기간 1993 ~ 2006
- 주제분류 공학 > 금속공학 공학 분류의 다른 간행물
- 십진분류KDC 559DDC 629
권호리스트/논문검색
한국분말야금학회 2006년도 춘계학술대회논문집 (2006년 4월) 443건
421.
2006.04
구독 인증기관·개인회원 무료
Development of recycling method at cemented carbide scraps was researched. Some properties of recycled cemented carbides were investigated. Recycled WC fine powder suffered the surface oxidation. Therefore it was necessary to be done by reduction treatment at 1073K-3.6ks under hydrogen atmosphere. When sintering condition at 1673K-3.6ks was treated under vacuum condition, it gained the deflective strength of about 90%, and gained hardness and sintering density about same value compared with commercial alloys. As a result, it was able to recycle only by 7 processes.
422.
2006.04
구독 인증기관·개인회원 무료
Sintered Ti(C,N)-based cermets were treated with hot isostatic pressing (HIP) at different nitrogen pressures. The tribological properties of the treated cermets have been evaluated. The results show that a hard near-surface area rich in TiN formed after HIP treatment. The cermets treated at higher pressure had a relatively lower friction coefficient and specific wear rate. In all cases the microhardness of treated cermets is higher than that without HIP natridation. The wear mechanisms of cermets were hard particle flaking-off and ploughing. It was also found that the HIP natridation is well-suited for improving the tribological properties of cermets.
423.
2006.04
구독 인증기관·개인회원 무료
Ur, Soon-Chul, Kwon, Joon-Chul, Choi, Moon-Kwan, Kweon, Soon-Yong, Hong, Tae-Whan, Kim, Il-Ho, Lee, Young-Geun
Undoped powders were synthesized by mechanical alloying (MA) of elemental powders using a nominal stoichiometric composition. Nano-structured, single-phase skutterudite was successfully produced by vacuum hot pressing (VHP) using MA powders without subsequent annealing. Phase transformations during synthesis were investigated using XRD, and microstructure was observed using SEM and TEM. Thermoelectric properties in terms of Seebeck coefficient, electrical conductivity, thermal conductivity and figure of merit(ZT) were systematically measured and compared with the results of analogous studies. Lattice thermal conductivity was reduced owing to increasing phone scattering in nano-structured MA , leading to enhancement in the thermoelectric figure of merit. MA associated with VHP technique offers an alternative potential processing route for the process of skutterudite.
424.
2006.04
구독 인증기관·개인회원 무료
425.
2006.04
구독 인증기관·개인회원 무료
The influence of doping on the structural and morphological properties of the phosphor system, obtained ultrasonically via Spray Pyrolysis from common gadolinium and europium nitrate solutions, was studied. The particle morphology, crystalline and chemical structure were studied by XRD, SEM and EDS. TEM was applied in order to identify the structure and growth of "primary nanoparticles" and determine the presence of domains locally affected by "Moires Frames" and "Crystallite Size". The SADP allows determining the presence of a polycrystalline material with two phases in the "as-prepared" samples, and only an Ia3 phase along the thermal treatment.
426.
2006.04
구독 인증기관·개인회원 무료
De la Torre, M. A. Lopez, Dura, O. J., Hernandez, M., Garcia-Cordobes, M., Herranz, G., Sanchez-Bautista, C., Rodriguez, G. P.
We report on the mechanical and structural properties of nanocrystalline 8% and 10% mol yttria stabilized zirconia (YSZ) obtained using mechanical alloying (MA). The as-milled powders show a body-centered cubic structure with grain sizes in the nanometer scale. After uniaxial pressing and sintering the compacts exhibit good mechanical properties. We discuss the correlation of these enhanced properties with the microstructural changes induced by heat treatment.
427.
2006.04
구독 인증기관·개인회원 무료
428.
2006.04
구독 인증기관·개인회원 무료
Talaka, Tatsiana, Grigorieva, Tatiana, Vitiaz, Piotr, Lyakhov, Nikolay, Letsko, Andrey, Beliaev, Andrey, Barinova, Antonina
429.
2006.04
구독 인증기관·개인회원 무료
The influence of several experimental parameters on the formation of stable Alloy 625 nanoparticles dispersion in ethanol was investigated. Several analyzing methods were applied, like transmission profiles measured by Turbiscan, transmission electron microscopy, X-ray diffraction, gas chromatography, and particle size analyzer. The correlation among the increase of particle sizes, caused by nanoparticle coalescence and collision, concentration of dispersant and time was presented and discussed. The optimum conditions for the formation of stable dispersion are evaluated.
430.
2006.04
구독 인증기관·개인회원 무료
431.
2006.04
구독 인증기관·개인회원 무료
Synthesis of zinc oxide nanorods, sheets and flower like structure were done by the sol-gel method using zinc acetate dihydrate and sodium hydroxide at with 12 hours refluxing time nanorods, in case of as synthesized powder, with diameter of 20-60nm. Annealing at higher temperature (300 and ,) in air ambient changes the morphology to sheet and flower like structure. The standard peak of zinc oxide was observed in IR at . The UV-VIS spectroscopy of zinc oxide shows a characteristic peak at 375nm.
432.
2006.04
구독 인증기관·개인회원 무료
The effects of particle size on the surface properties of hydro-thermally synthesized barium titanate powders were investigated by means of particle size analysis, specific surface area, SEM, zeta potential and XPS. Particle sizes were measured by laser light scattering and are in the range of 150 to 1100nm. Zeta potential increased with increasing particle size and it was large minus value in the range of particle size from 500 to 900nm, which seems to be related with the dissolution of ion in these particle sizes from the analysis of surface properties by XPS.
433.
2006.04
구독 인증기관·개인회원 무료
Lomovsky, O.I., Dudina, D.V., Korchagin, M.A., Kosarev, V.F., Klinkov, S.V., Ulianitsky, V.Yu., Kim, J.S., Kwon, Y.S.
434.
2006.04
구독 인증기관·개인회원 무료
435.
2006.04
구독 인증기관·개인회원 무료
436.
2006.04
구독 인증기관·개인회원 무료
Shikatani, Noboru, Misawa, Tatsuya, Ohtsu, Yasunori, Fujita, Hiroharu, Kawakami, Yuji, Enjoji, Takashi
Thermoelectric conversion efficiency of thermoelectric elements can be increased by using a structure combining n-type and p-type semiconductors. From the above point of view, attention was directed at ZnO as a candidate n-type semiconductor material and investigations were made. As the result, a dimensionless figure of merit ZT close to 0.28 (1073K) was obtained for specimens produced by the PCS (Pulse Current Sintering) method with addition of specified quantities of , CoO, and to ZnO. It was found that the interstitial in the ZnO restrains the grain growth and CoO acts onto the bond between grains. The influence of the inclusion of and CoO onto the sintering behavior also was investigated.
437.
2006.04
구독 인증기관·개인회원 무료
In the present study, the powder metallurgical fabrication of thermoelectric materials has been studied with specific interest to control the microstructure by the mechanical grinding process. The thermoelectric powders with a various particle size distribution were prepared by the combination of the mechanical milling and blending processes. The specific electric resistivity of the sintered bodies mainly depended on the orientation of the crystal structure rather than the particle size of the raw powders.
438.
2006.04
구독 인증기관·개인회원 무료
The encapsulated induction melting and hot pressing were employed to prepare Fe-doped skutterudites and their thermoelectric properties were investigated. Single phase was successfully obtained by the subsequent heat treatment at 773K for 24 hours. Iron atoms acted as electron acceptors by substituting cobalt atoms. Thermoelectric properties were remarkably improved by the appropriate doping. was found as an optimum composition for best thermoelectric properties in this work.
439.
2006.04
구독 인증기관·개인회원 무료
Ni-doped was prepared by the encapsulated induction melting and hot pressing, and its doping effects on the thermoelectric properties were investigated. Single phase was successfully obtained by the subsequent heat treatment at 773K for 24 hours. Nickel atoms acted as electron donors by substituting cobalt atoms. Thermoelectric properties were remarkably improved by the appropriate doping.
440.
2006.04
구독 인증기관·개인회원 무료
Variable valve timing unit, which is able to decrease environmental load and improve fuel economy is loaded onto many automobiles recently. This unit consists mainly of sprocket, housing and rotor. These parts are requested different properties according to environment. We produce sintered parts for variable valve timing unit by selecting compact, sinter process and special treatment according to demanded properties. In this paper, demanded properties of sintered parts for variable valve timing unit and adopted technique to satisfy them are presented.
