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 추계학술대회논문집 (2006년 9월) 358건
301.
2006.09
구독 인증기관·개인회원 무료
To co-fire with commercial LTCC (Low Temperature Co-fired Ceramic) materials at , different contents of were added to the (BZN) ceramics. According to the test results, the cubic phase of BZN was transformed into orthorhombic in all the test materials. phase was formed in test materials with of addition. The phase transformation of cubic BZN was controlled during the synthesis process with excess ZnO content. The Cubic and orthorhombic phases of BZN could coexist and be sintered densely at .
302.
2006.09
구독 인증기관·개인회원 무료
Considering the idea that some properties, especially the mechanical properties of at ambient temperature can be improved by adding of some substitutional/interstitial elements, our goal was to obtain these materials starting from mechano-composites powders. In this aim, using mechanical alloying techniques three type of mechano-composite powders starting from elemental powders were obtained. Then, by reactive sintering in argon atmosphere at temperature over , alloyed materials were realized. This paper presents our research results regarding the microstructural aspects and phase formation in obtained materials.
303.
2006.09
구독 인증기관·개인회원 무료
304.
2006.09
구독 인증기관·개인회원 무료
305.
2006.09
구독 인증기관·개인회원 무료
306.
2006.09
구독 인증기관·개인회원 무료
Effects of doping on the electromagnetic properties in the BiSrCaCuO superconductors. The electromagnetic properties of doped and undoped BiSrCaCuO superconductor were evaluated to investigate the contribution of the pinning centers to the magnetic effect. It was confirmed experimentally that a large amount of magnetic flux was trapped in the doped sample than that in the undoped one, indicating that the pinning centers of magnetic flux are related closely to the occurrence of the magnetic effect. It is considered that the area where normal conduction takes place increases by adding and the magnetic flux penetrating through the sample increases. The results suggested that Ag acts to increase pinning centers of magnetic flux, contributing to the occurrence of the electromagnetic properties.
307.
2006.09
구독 인증기관·개인회원 무료
Electromagnetic properties of doped and undoped YBaCuO superconductors were evaluated to investigate the effect of pinning center on the magnetization and magnetic shielding. The variation with doping was maximum for 3% doping and decrease with further doping. The magnetic shielding was evaluated by measuring the induced voltage in secondary coil and the voltage initially set to 0.5V, decreased to 0.17V and 0.28V respectively for the undoped and 3% doped sample. The much less change in the induced voltage for the 3% doped sample is attributed to the increased flux shielding by shielding vortex current. The was converted to fine particles which were trapped in YBaCuO superconductor during the reaction sintering. The trapped fine particles, may be acted as a flux pinning center.
308.
2006.09
구독 인증기관·개인회원 무료
Five kinds of double stacked 385 (55 x7) filamentary Bi2212/Ag round wires and 55 filamentary tapes with different Ag ratios (silver area/superconductor area) have been fabricated via PIT method, and the effects of Ag ratio and processing factors on critical current density were studied. The effects of the maximum temperature and average filament diameter on critical current density were also studied. The wire of 0.74 mm diameter having Ag ratio 3.7 showed critical current density of at 4.2 K, 0 T.
309.
2006.09
구독 인증기관·개인회원 무료
Kim, Kyu-Tae, Jang, Seok-Hern, Lim, Jun-Hyung, Park, Eui-Cheol, Joo, Jin-Ho, Lee, Hoo-Jeong, Hong, Gye-Won, Kim, Chan-Joong, Kim, Hye-Rim, Hyun, Ok-Bae
We fabricated Bi-2212/ composite superconductors and evaluated the effects of the powder mixing method and melting temperature on their microstructure and superconducting properties. The Bi-2212 powders were mixed with by hand-mixing (HM) and planetary ball milling (PBM) and then the powder mixtures were melted at , solidified, and annealed. We found that the powder mixture prepared by PBM was finer and more homogeneously mixed than that prepared by HM, resulting in more homogeneous microstructure and smaller and second phases after annealing.
310.
2006.09
구독 인증기관·개인회원 무료
Lim, Jun-Hyung, Jang, Seok-Hern, Yoon, Kyung-Min, Lee, Seung-Yi, Joo, Jin-Ho, Lee, Hoo-Jeong, Kim, Chan-Joong
We fabricated YBCO film using a TFA-MOD method. In order to enhance the reaction kinetics and to control the formation of the second phases, and powders were used as precursors (the so called "211 process"). The films were calcined at and then fired at in a 12.1% humidified atmosphere. We found that the microstructure varied significantly with the firing temperature. The textures of all of the films were similar and mainly biaxial. For the film fired at , the critical current was obtained to be 39 A/cm-width (corresponding critical current density is 2.0 MA/).
311.
2006.09
구독 인증기관·개인회원 무료
Lim, Jun-Hyung, Kim, Kyu-Tae, Park, Eui-Cheol, Joo, Jin-Ho, Kim, Hyoung-Sub, Lee, Hoo-Jeong, Jung, Seung-Boo, Nah, Wan-Soo
Cube textured Ni substrate were fabricated for YBCO coated conductors from the initial specimens prepared by powder metallurgy (P/M) and casting and the effects of annealing temperature and reduction ratio on texture formation and microstructural evolution were evaluated. The initial specimens were rolled and then annealed in the temperature at . A strong cube texture formed for P/M substrate, and the degree of texture did not significantly vary with annealing temperature of . On the other hand, the texture of casting substrate was more dependent on the annealing temperature and twin texture and several minor texture components started to form at .
312.
2006.09
구독 인증기관·개인회원 무료
In order to investigate 95% retained critical current of Bi-2223/Ag tapes under various stress-strain conditions, load cell attached tension and bending apparatus was used. The critical current of stress-strained tape was degraded below 95% retained critical current when tension and bending was simultaneously applied together. But only one of this tension or bending did not degrade the tape below 95% retained critical current. Deformation temperature was important to maintain the 95% retained Ic of Bi-2223/Ag tapes after bending or tension deformation because mechanical strength of tapes can be changed drastically between room temperature and 77 K.
313.
2006.09
구독 인증기관·개인회원 무료
314.
2006.09
구독 인증기관·개인회원 무료
For precise property control of sintered products, it is important to understand accurately the packing density of the powder. We developed a packing simulation program that could make a packed bed of spherical particles having particle size distribution. In addition, the influence of the particle shape of the actual powder on the packing density was quantitatively analyzed. The predicted packing densities corresponded well to the actual data.
315.
2006.09
구독 인증기관·개인회원 무료
316.
2006.09
구독 인증기관·개인회원 무료
Biomimetic apatite deposition behaviors and mechanical performance for as-rolled and annealed Ni-Ti plates were investigated . A good biomimetic apatite formation and excellent mechanical performance of Ni-Ti suggests that Ni-Ti can be an excellent candidate material as orthopedic implants.
317.
2006.09
구독 인증기관·개인회원 무료
Intensive technological research on the Dry-bag CIP equipment was carried out to improve the dimensional accuracy and the productivity. The rubber mold design technology using FEM simulation during pressing was introduced, in order to achieve higher dimensional preciseness, and criteria for the selection of the In-line type or Off-line type, were established based on the powder flowability index proposed by Carr. Based on these research results, high productivity Off-line Dry-bag CIP equipment, which can realize good dimensional accuracy with high productivity, was developed even for non-granulated powders with poor packing density.
318.
2006.09
구독 인증기관·개인회원 무료
319.
2006.09
구독 인증기관·개인회원 무료
Study about the feasibility and effect of high-energy ball milling on a specific Mg alloy under protection medium of alcohol was presented via comparing with conventional vacuum milling. More fine particles with wider powder size distribution but more irregular shape were shown of the powder milled under alcohol. No obvious oxide was revealed from the two kinds of Mg alloy powders with limited milling time. And since slip induced in a preferential direction, the (002) texture was formed in the Mg alloy powders at the initial stage of alcohol milling. More O and Fe contaminants were introduced into the powders milled under alcohol according to the EDS analysis.
320.
2006.09
구독 인증기관·개인회원 무료
alloy powders were prepared using an industrial scale gas atomizer, followed by warm extrusion. The powders were almost spherical in shape. The microstructure of powders as atomized and bars as extruded was examined as a function of initial powder size distribution using Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscope (EDS) and X-ray Diffractometer (XRD). The grain sizes were decreased with extruding as well as decreasing the initial powder sizes. Both the ultimate strength and elongation were enhanced as the initial powder sizes were decreased.
