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Wyszukujesz frazę "Kim, T.-J." wg kryterium: Autor


Tytuł:
An analysis on the thermal characteristics according to the viscosity of bearing lubricant and the cooling condition for the high speed motor spindle
Autorzy:
Choi, D. B.
Lee, J. J.
Kim, S. T.
Kwon, H. D.
Kim, C. Y.
Powiązania:
https://bibliotekanauki.pl/articles/1429194.pdf
Data publikacji:
2008
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
high speed motor spindle
thermal displacement cooling condition
lubricant viscosity
Opis:
Thermal displacement of the high speed machine tools has a large influence on machining accuracy. The high speed motor spindle with many heat sources is widely used for the high speed machine tools recently. The important problem in this spindle is to reduce and minimize the thermal effects by motor and bearings. This paper presents the analysis on thermal characteristics for high speed motor spindle system with oil-air lubricated angular contact ceramic ball bearings and built-in motor. An analysis on the thermal characteristics of spindle is performed according to the cooling conditions and the viscosity of bearing lubricants by using finite element method. This results can be applied to the design and manufacturing for the high speed motor spindle.
Źródło:
Journal of Machine Engineering; 2008, 8, 4; 88-98
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carbon Co-Deposition During Gas Reduction of Water-Atomized Fe-Cr-Mo Powder
Autorzy:
Ali, B.
Choi, S. H.
Seo, S. J.
Maeng, D. Y.
Lee, C. G.
Kim, T. S.
Park, K. T.
Powiązania:
https://bibliotekanauki.pl/articles/352709.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
water atomization
Fe-based powder
oxide reduction
powder metallurgy
sinter-hardening alloys
Opis:
The water atomization of iron powder with a composition of Fe-3Cr-0.5Mo (wt.%) at 1600°C and 150 bar creates an oxide layer, which in this study was reduced using a mixture of methane (CH4) and argon (Ar) gas. The lowest oxygen content was achieved with a 100 cc/min flow rate of CH4, but this also resulted in a co-deposition of carbon due to the cracking of CH4. This carbon can be used directly to create high-quality, sinter hardenable steel, thereby eliminating the need for an additional mixing step prior to sintering. An exponential relationship was found to exist between the CH4 gas flow rate and carbon content of the powder, meaning that its composition can be easily controlled to suit a variety of different applications.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 1119-1124
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Causal relationship between supply chain dynamic capabilities, technological innovation, and operational performance
Autorzy:
Ju, K.-J.
Park, B.
Kim, T.
Powiązania:
https://bibliotekanauki.pl/articles/407389.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
supply chain management
dynamic capabilities
supply chain dynamic capabilities
technological innovation
operational performance
Opis:
The aim of this study is to empirically examine the impact of supply chain dynamic capabilities on operational performance, and the mediating effect of technological innovation between dynamic capabilities and operational performance. This study is based on empirical data collected from a survey of 206 small- and medium-size firms in Korea. Structural equation modeling is used to test the research questions. The results show that supply chain dynamic capabilities positively influence technological innovation and operational performance of an enterprise. Additionally, structural equation analyses reveal that technological innovation plays a role as a partial mediator of the relationship between supply chain dynamic capabilities and operational performance. In a dynamic and ever-changing environment, the enforcement of dynamic capabilities in a sustainable supply chain is important for the innovation of technology and the improvement of operational performance. Further investigation is required to understand the differences by industries, characteristics of enterprises, and positions in a supply chain.
Źródło:
Management and Production Engineering Review; 2016, 7, 4; 6-15
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of Cu and Ni Nano-Fluids Synthesized by Pulsed Wire Evaporation Method
Autorzy:
Kim, H.-S.
Yilmaz, F.
Dharmaiah, P.
Lee, D.-J
Lee, T.-H.
Hong, S.-J.
Powiązania:
https://bibliotekanauki.pl/articles/356475.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pulsed wire evaporation
nanofluid
Cu
Ni
suspension stability
dispersibility
Opis:
In the present work, Cu and Ni nanofluids were synthesized using the pulsed wire evaporation (PWE) method in the different aqueous medias, namely (ethanol and ethylene glycol), and the effects of the aqueous media on the dispersion state, stability, and particle size of nanoparticles were studied. The size and morphology of synthesized nano-particles were investigated by transmission electron microscopy (TEM). Also, the dispersion stability of the nanofluids was evaluated by turbiscan analysis. The TEM results showed that the nano-particles were spherical in shape, and the average particle size was below 100 nm. The average particle size of the Cu nano-particles was smaller than that of Ni, which was attributed to a difference in the specific sublimation energy of the elements. Moreover, ethylene glycol (EG) exhibited higher suspension stability than ethanol. Finally, the dispersion stability of Cu@EG displayed the highest value due to lower particle size and greater viscosity.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 999-1004
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of body surface area-based and weight-based dosing format for oral prednisolone administration in small and large-breed dogs
Autorzy:
Nam, A.
Kim, S.M.
Jeong, J.W.
Song, K.H.
Koo, T.S.
Seo, K.W.
Powiązania:
https://bibliotekanauki.pl/articles/2087897.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Źródło:
Polish Journal of Veterinary Sciences; 2017, 3; 611-613
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation Between Superheated Liquid Fragility And Onset Temperature Of Crystallization For Al-Based Amorphous Alloys
Korelacja między krytycznymi parametrami cieczy i temperaturą początku krystalizacji dla amorficznych stopów na bazie Al
Autorzy:
Guo, J.
Hu, X.
Liu, J.
Feng, T.
Yoon, E. Y.
Kim, H. S.
Powiązania:
https://bibliotekanauki.pl/articles/353707.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
superheated liquid fragility
onset temperature of crystallization
thermal stability
krytyczny parametr cieczy
temperatura początku krystalizacji
stabilność termiczna
Opis:
Amorphous alloys or metallic glasses have attracted significant interest in the materials science and engineering communities due to their unique physical, mechanical, and chemical properties. The viscous flow of amorphous alloys exhibiting high strain rate sensitivity and homogeneous deformation is considered to be an important characteristic in thermoplastic forming processes performed within the supercooled liquid region because it allows superplastic-like deformation behavior. Here, the correlation between the superheated liquid fragility, and the onset temperature of crystallization for Al-based alloys, is investigated. The activation energy for viscous flow of the liquid is also investigated. There is a negative correlation between the parameter of superheated liquid fragility and the onset temperature of crystallization in the same Al-based alloy system. The activation energy decreases as the onset temperature of crystallization increases. This indicates that the stability of a superheated liquid can affect the thermal stability of the amorphous alloy. It also means that a liquid with a large superheated liquid fragility, when rapidly solidified, forms an amorphous alloy with a low thermal stability.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2B; 1543-1546
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect Of Carbon Nanotubes On The Properties Of Spark Plasma Sintered ZrO2/CNT Composites
Wpływ nanorurek węglowych na właściwości spiekanych metodą sps kompozytów ZrO2/CNT
Autorzy:
Shim, D. H.
Jung, S. S.
Kim, H. S.
Cho, H.
Kim, J. K.
Kim, T. G.
Yoon, S. J.
Powiązania:
https://bibliotekanauki.pl/articles/351266.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
CNT
ZrO2
composite
SPS
kompozyty
Opis:
Zirconia matrix ZrO2/CNT composite materials reinforced with multiwall carbon nanotubes were fabricated using a spark plasma sintering technique. The effects of the amount of CNTs addition, sintering temperature and sintering pressure on the properties of the resulting ZrO2/CNT composites were examined. 0 to 9 vol. % CNTs were dispersed in zirconia powder, and the resulting mixture was sintered. The electrical conductivity, hardness, flexural strength, and density were measured to characterize the composites. The friction and wear properties of the composites were also tested. The flexural strength and friction coefficient of the composites were improved with up to 6 vol.% of CNT addition and the flexural strength showed a close relationship with the relative density of the composite. The electrical conductivity increased with increasing proportion of the CNTs, but the efficiency was reduced at more than 6 vol.% CNTs.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2B; 1315-1318
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect Of Different Mechanical Milling Processes On Morphology And Microstructural Changes Of Nano And Micron Al-Powders
Wpływ różnych procesów mielenia na morfologię i mikrostrukturę nanometrycznych i mikronowych proszków Al
Autorzy:
Kim, H.-S.
Madavali, B.
Eom, T.-J.
Kim, C.- M.
Koo, J.-M.
Lee, T. H.
Hong, S.-J.
Powiązania:
https://bibliotekanauki.pl/articles/355715.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al alloys
high-energy ball milling
low energy ball milling
plastic deformation
stopy Al
wysokoenergetyczne mielenie kulkowe
mielenie energooszczędne
odkształcenia plastyczne
Opis:
In this research, effect of the various mechanical milling process on morphology and microstructural changes of nano and micron Al-powders was studied. The milling of Al-powders was performed by both high energy and low energy ball milling process. The influence of milling (pulverizing) energy on the structural changes of Al-powders was studied. Al-nanoparticles were agglomerated during the MA and its size was increased with increasing milling while micron Al-powder gets flattened shape during high energy ball milling due to severe plastic deformation. Meanwhile, structural evolution during high energy ball milling of the nano powder occurred faster than that of the micron powder. A slight shift in the position of X-ray diffraction peaks was observed in nano Al-powders but it was un-altered in macro Al-powders. The variation in lattice parameters was observed only for nano Al powders during the high energy ball milling due to lattice distortion.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2B; 1235-1239
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect Of DyMn Alloy-Powder Addition On Microstructure And Magnetic Properties Of NdFeB Sintered Magnets
Wpływ dodatku proszku DyMn na mikrostrukturę i właściwości magnetyczne spiekanych magnesów NdFeB
Autorzy:
Lee, M.-W.
Dhakal, D. R.
Kim, T. H.
Lee, S. R.
Kim, H. J.
Jang, T. S.
Powiązania:
https://bibliotekanauki.pl/articles/357010.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Nd-Fe-B sintered magnets
DyMn-alloy powder
coercivity
low melting point element
magnesy spiekane
proszek DyMn
koercja
elementy o niskiej temperaturze topnienia
Opis:
Micostructural change and corresponding effect on coercivity of a NdFeB sintered magnet mixed with small amount of DyMn powder was investigated. In the sintered magnet mixed with the DyMn alloy-powder Dy-rich shell was formed at outer layer of the main grains, while Mn was mostly concentrated at Nd-rich triple junction phase (TJP), lowering melting temperature of the Nd-rich phase that eventually improved the microstructural characteristics of the gain boundary phase. The coercivity of a magnet increased more than 3.5 kOe by the mixing of the DyMn alloy-powder.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2B; 1407-1409
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Trace Elements (Co, Cr) on the Microstructure and Physical Properties of Al-Si-Cu-Mg-Fe Extruded Alloy
Autorzy:
Ahn, S. S.
Sharief, P.
Lee, C. H.
Son, H. T.
Kim, Y. H.
Kim, Y. C.
Hong, S.
Hong, S. J.
Powiązania:
https://bibliotekanauki.pl/articles/352787.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al-Si alloy
microstructure
extrusion
coefficient of thermal expansion
trace elements
Opis:
Trace elements Co, Cr were added to investigate their influence on the microstructure and physical properties of Al-Si extruded alloy. The Co, Cr elements were randomly distributed in the matrix, forms intermetallic phase and their existence wereconfirmed by XRD, EDS and SEM analysis. With addition of trace elements, the microstructure was modified, Si particle size was reduced and the growth rate of β-(Al5 FeSi) phase limited. Compared to parent alloy, hardness and tensile strength were enhanced while the linear coefficient of thermal expansion (CTE) was significantly reduced by 42.4% and 16.05% with Co and Cr addition respectively. It is considered that the low CTE occurs with addition of Co was due to the formation of intermetallic compound having low coefficient of thermal expansion. The results suggested that Co acts as an effective element in improving the mechanical properties of Al-Si alloy.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 3; 857-862
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication and Characterization of CoCrFeNiMn High Entropy Alloy Powder Processed by Gas Atomization
Autorzy:
Park, T. G.
Lee, S. H.
Lee, B.
Cho, H. M.
Choi, W. J.
Kim, B. S.
Shin, K. S.
Kim, T.-S.
Powiązania:
https://bibliotekanauki.pl/articles/353649.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high entropy alloy
gas atomization
spark plasma sintering
CoCrFeNiMn
Opis:
In this study, precisely controlled large scale gas atomization process was applied to produce spherical and uniform shaped high entropy alloy powder. The gas atomization process was carried out to fabricate CoCrFeNiMn alloy, which was studied for high ductility and mechanical properties at low temperatures. It was confirmed that the mass scale, single phase, equiatomic, and high purity spherical high entropy alloy powder was produced by gas atomization process. The powder was sintered by spark plasma sintering process with various sintering conditions, and mechanical properties were characterized. Through this research, we have developed a mass production process of high quality and spherical high entropy alloy powder, and it is expected to expand applications of this high entropy alloy into fields such as powder injection molding and 3D printing for complex shaped components.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 1055-1059
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication of a Spherical Titanium Powder by Combined Combustion Synthesis and DC Plasma Treatment
Autorzy:
Choi, S. H.
Ali, B.
Hyun, S. K.
Sim, J. J.
Choi, W. J.
Joo, W.
Lim, J. H.
Lee, Y. J.
Kim, T. S.
Park, K. T.
Powiązania:
https://bibliotekanauki.pl/articles/356067.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
combustion synthesis
DC plasma treatment
titanium powder
3D printing process
combustion parameters
Opis:
Combustion synthesis is capable of producing many types of refractory and ceramic materials, as well as metals, with a relatively lower cost and shorter time frame than other solid state synthetic techniques. TiO2 with Mg as reductant were dry mixed and hand compacted into a 60 mm diameter mold and then combusted under an Ar atmosphere. Depending on the reaction parameters (Mg concentration 2 ≤ α ≤ 4), the thermocouples registered temperatures between 1160°C and 1710°C . 3 mol of Mg gave the optimum results with combustion temperature (Tc) and combustion velocity (Uc) values of 1372°C and 0.26 cm/s respectively. Furthermore, this ratio also had the lowest oxygen concentration in this study (0.8 wt%). After combustion, DC plasma treatment was carried out to spheroidize the Ti powder for use in 3D printing. The characterization of the final product was performed using X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and N/O analysis.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 1057-1062
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication Of Porous Ti By Thermal Decomposition And Sintering Of PMMA/TiH2 Powder Compact
Wytwarzanie porowatego tytanu przez rozkład termiczny i spiekanie wyprasek PMMA/TiH2
Autorzy:
Jeon, K. Ch.
Kim, Y. D.
Suk, M.-J.
Oh, S.-T.
Powiązania:
https://bibliotekanauki.pl/articles/352341.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
porous Ti
PMMA powders
thermal decomposition of TiH2
pore structure
porowaty tytan
PMMA
rozkład termiczny
struktura porów
Opis:
Porous Ti with controlled pore structure was fabricated by thermal decomposition and sintering process using TiH2 powders and Polymethylmethacrylates (PMMA) beads as pore forming agent. The beads sizes of 8 and 50 μm were used as a template for fabricating the porous Ti. The TiH2 powder compacts with 20 and 70 vol% PMMA were prepared by uniaxial pressing and sintered for 2 h at 1100°C. TGA analysis revealed that the PMMA and TiH2 were thermally decomposed at about 400°C forming pores and at about 600°C into metallic Ti phase. The porosity increased with increase in the amount of PMMA addition. Also, the microstructure observation showed that the pore size and shape were strongly dependent on the PMMA shapes.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2B; 1375-1377
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Formation of Different Cu Nanopowders and Stability of Cu Fluids Produced by Electrical Explosion of Wire in Liquid
Autorzy:
Nguyen, M.-T.
Kim, J.-H.
Kim, J.-C.
Powiązania:
https://bibliotekanauki.pl/articles/355217.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Cu nanopowder
Cu nanofluids
electrical explosion of wire
stability of nanofluids
Opis:
In this study, copper nanoparticles and nanofluids were synthesized by electrical explosion of wire (EEW) in liquid media such as water, ethanol, and acetone. The effect of the different conditions on the properties of the as-synthesized Cu powders and nanofluids were investigated. X-ray diffraction (XRD) analysis was employed to measure the phase of the as-synthesized powder. Only pure Cu phase appeared in case of acetone condition, but CuO and CuO2 phases could be observed in the others. The EEWed particle size was broadened from under 50 to 100 nm. The results showed that acetone was the best condition for achieving smaller particles, preventing the oxidation of the Cu particles and good stability of the nanofluids.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 3; 1453-1457
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hardness and Microstructure of Mixed Al-CNF Powder Extrusion
Autorzy:
Kim, D.-H.
Kim, T.-J.
Lim, S.-G.
Powiązania:
https://bibliotekanauki.pl/articles/351170.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al-CNF composite
cold isotatic
presses
powder extrusion
LED
microstructure
Opis:
In this study, mechanical properties and microstructures of extruded aluminum matrix composites were investigated. The composite materials were manufactured by two step methods: powder metallurgy (mixture of aluminum powder and carbon fiber using a turbular mixer, pressing of mixed aluminum powder and carbon fiber using a cold isostatic pressing) and hot extrusion of pressed aluminum powder and carbon fiber. For the mixing of Al powder and carbon fibers, aluminum powder was used as a powder with an average particle size of 30 micrometer and the addition of the carbon fibers was 50% of volume. In order to make mixing easier, it was mixed under an optimal condition of turbular mixer with a rotational speed of 60 rpm and time of 1800s. The process of the hot-extrusion was heated at 450°C for 1 hour. Then, it was hot-extruded with a condition of extrusion ratio of 19 and ram speed of 2 mm/s. The microstructural analysis of extruded aluminum matrix composites bars and semi-solid casted alloys were carried out with the optical microscope, scanning electron microscope and X-ray diffraction. Its mechanical properties were evaluated by Vickers hardness and tensile test.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 1267-1270
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł

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