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    Wyświetlanie 1-27 z 27
    Tytuł:
    Structural Properties and Mechanical Behavior of the 2 Step-Reinforced Al-Si/SiCp Metal Matrix Composite by Titanium-Fiber
    Autorzy:
    Oak, J.-J.
    Lee, Y. C.
    Park, Y. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/356010.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    metal matrix composite
    sintering
    Ti fiber
    mechanical properties
    diffusion
    Opis:
    In this study, the newly designed Al-9Si/SiC particles (SiCp) + Ti-fiber (2step-reinforced Al-9Si alloy matrix) metal matrix composites (MMCs) were fabricated by hot-pressing sintering at 560°C. 2step-reinforced Al-based MMCs were characterized by thermal shrinkage, phase transition, microstructure and tensile strength. The addition of Ti-fiber reduced thermal shrinkage was caused by temperature difference in sintering process as well as enhanced assistance for tensile strength and plastic deformation at room temperature. Experimental results reveal that the 2step-reinforcment sintering by ceramic and metal has a significant effect to increase interface bonding in boundary of each component material and the improved mechanical properties were due to the influence of interfacial product by diffusion. Tensile strength and elongation at room temperature by 2step-reinforcement were improved in 19.5% and 26.2% more than those of Al-9Si/SiCp, respectively. Especially, it reveals that diffusion direction may be varied by sintering methods at low temperature in this study.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1089-1097
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Alumina Coating To Realize Desired Pore Characteristics Of Sintered Diatomite Membrane
    Powłoka tlenku glinu do uzyskania pożądanej porowatości spiekanej membrany diatomitowej
    Autorzy:
    Ha, J. H.
    Park, Y.-H.
    Song, I.-H.
    Powiązania:
    https://bibliotekanauki.pl/articles/354776.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    diatomite membrane
    alumina coatings
    largest pore size
    membrana diatomitowa
    powłoka tlenku glinu
    porowatość
    Opis:
    Porous ceramic membranes prepared from natural materials such as diatomite, have lately attracted great interest in industrial applications due to their cost-effectiveness. In this study, we attempted to prepare an alumina coating to be deposited over a sintered diatomite-kaolin composite support layer in order to reduce the largest pore size to below 0.4 μm; such a coating could be potentially used in water treatment applications for bacterial removal.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1175-1178
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Hafnium and Zirconium to Glass Forming Ability, Thermal Stability, Plasticity Deformation and Crystallization of Ni-Free Pentabasic Ti-Based Bulk Metallic Glasses
    Autorzy:
    Oak, J.-J.
    Kim, Y. H.
    Bae, K.-C.
    Park, Y. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/352087.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Ti-based alloy
    metallic glass
    Ti fiber
    glass formability
    plastic deformation
    Opis:
    The newly designed Ti-based bulk metallic glass (BMG) in which case of fracture behavior was observed 1990MPa to compressive strength with a wide plastic deformation around 7% after process of elastic deformation. This phenomenon can be compared with those of Ti-based alloys and other Ti-based BMGs and indicates high potential to be applied in use. It was evaluated the Ti-based BMG for thermal stability that the reduced glass parameters, ΔTx, Trg and γ, are 79K, 0.50 and 0.38, respectively. In addition, it reveals high activation energies for crystallization in which are estimated to Ex1 = 291.77 ±9.71 kJ/mol, Ex2 = 588.77 ±28.88 kJ/mol and Ex3 = 330.26 ±3.61 kJ/mol on kissinger plotting in this study.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1081-1087
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Fe Content on the Microstructure and Mechanical Properties of Ti-Al-Mo-V-Cr-Fe Alloys
    Autorzy:
    Bae, K.-C.
    Oak, J.-J.
    Kim, Y. H.
    Park, Y. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/351896.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Ti alloy
    near-β titanium alloy
    aircraft applications
    structural material
    landing gear
    Opis:
    To investigate the effect of Fe content on the correlation between the microstructure and mechanical properties in near-b titanium alloys, the Ti-5Al-5Mo-5V-1Cr-xFe alloy system has been characterized in this study. As the Fe content increased, the number of nucleation sites and the volume fraction of the α phase decreased. We observed a significant difference in the shape and size of the α phase in the matrix before and after Fe addition. In addition, these morphological deformations were accompanied by a change in the shape of the α phase, which became increasingly discontinuous, and changed into globular-type α phase in the matrix. These phenomena affected the microstructure and mechanical properties of Ti alloys. Specimen #2 exhibited a high ultimate tensile strength (1071 MPa), which decreased with further addition of Fe.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1105-1108
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    High-temperature Oxidation Behavior and Kinetics of Forged 12Cr-MoVW Steel
    Autorzy:
    Kim, Y. H.
    Oak, J.-J.
    Bae, K.-C.
    Lee, W-J.
    Park, Y. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/351450.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    ferritic/martensitic stainless steels
    forging
    oxidation kinetics
    oxide layer
    Opis:
    The oxidation kinetics of forged 12Cr-MoVW steel was investigated in an air (N2+O2) atmosphere at 873-1073 K (Δ50 K) using thermogravimetric analysis. The oxidized samples were characterized using X-ray diffraction, and the surface and cross-sectional morphologies were examined using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. The forged 12Cr-MoVW steel samples exhibited parabolic behavior and a low oxidation rate compared with their as-cast counterparts. A protective oxide layer was uniformly formed at relatively low temperature (≤973 K) for the forged samples, which thus exhibited better oxidation resistance than the as-cast ones. These oxides are considered solid-solution compounds such as (Fe, Cr)2O3.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1099-1104
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Characterization Of The Graded Microstructure In Powder Sintered Porous Titanium
    Charakterystyka gradientowej mikrostruktury porowatego tytanu spiekanego z proszku
    Autorzy:
    Oak, J.-J.
    Bang, J. I.
    Bae, K.-C.
    Kim, Y. H.
    Lee, Y. C.
    Chun, H. H.
    Park, Y. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/356239.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    titanium
    powder metallurgy
    porous structure
    sintering
    biomaterial
    tytan
    metalurgia proszków
    struktura porowata
    spiekanie
    biomateriał
    Opis:
    The proposed sintering process produce porosity and functional graded microstructure in the sinterd titanium powders. Titanium powders with different micro sizes were sintered at the proposed temperature region at 1200 and 1300°C for 2h. The apatite-forming on the graded microstructure is observed by immersion test in Hanks balanced salt soluion at 37°C. Sintering condition of titanium powders is estimated by thermogravitmetry-differential thermal analysis (TG-DTA). The synthersied surface structures and apatite-forming ability were characterized by a field emission scanning electron microscopy (FE-SEM) observation and energy dispersive X-ray spectroscopy (EDS) analysis. As results, these graded microstructure of sintered porous titanium powders reveals apatite-forming ability as osseointegration by calcification in Hanks balanced salt soluion(HBSS) at 37°C.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1265-1269
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Factor Analysis of Safety for Visitors to a Mega-Event
    Autorzy:
    Kwon, Y. G.
    Park, H. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/90888.pdf
    Data publikacji:
    2002
    Wydawca:
    Centralny Instytut Ochrony Pracy
    Tematy:
    factor analysis
    safety
    mega-event
    event tourism
    czynniki bezpieczeństwa
    bezpieczeństwo uczestników imprez
    turystyka
    Opis:
    This paper investigated the safety factors considered by visitors to the Kwangju Biennale 2000 and analyzed the correlation between the safety factors and the demographic characteristics of the visitors. Global tourism increased throughout the 1990s, with the biggest surge occurring in the Asia-Pacific region. Long-distance travel is also increasing, and at a rate faster than the global average. The opportunities for event tourism appear to be strong almost everywhere, even though recessions may have an impact on these destinations. Along with this upward trend, competition for more desirable tourists is also surging (Getz, 1997). Therefore event tourism is appearing as a powerful method in the fierce competition around the tourism industry.
    Źródło:
    International Journal of Occupational Safety and Ergonomics; 2002, 8, 3; 365-375
    1080-3548
    Pojawia się w:
    International Journal of Occupational Safety and Ergonomics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analysis of correlation based dimension reduction methods
    Autorzy:
    Shin, Y. J.
    Park, C. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/907508.pdf
    Data publikacji:
    2011
    Wydawca:
    Uniwersytet Zielonogórski. Oficyna Wydawnicza
    Tematy:
    analiza korelacyjna
    redukcja wymiaru
    liniowa analiza dyskryminacji
    canonical correlation analysis
    dimension reduction
    discriminative canonical correlation analysis
    linear discriminant analysis
    Opis:
    Dimension reduction is an important topic in data mining and machine learning. Especially dimension reduction combined with feature fusion is an effective preprocessing step when the data are described by multiple feature sets. Canonical Correlation Analysis (CCA) and Discriminative Canonical Correlation Analysis (DCCA) are feature fusion methods based on correlation. However, they are different in that DCCA is a supervised method utilizing class label information, while CCA is an unsupervised method. It has been shown that the classification performance of DCCA is superior to that of CCA due to the discriminative power using class label information. On the other hand, Linear Discriminant Analysis (LDA) is a supervised dimension reduction method and it is known as a special case of CCA. In this paper, we analyze the relationship between DCCA and LDA, showing that the projective directions by DCCA are equal to the ones obtained from LDA with respect to an orthogonal transformation. Using the relation with LDA, we propose a new method that can enhance the performance of DCCA. The experimental results show that the proposed method exhibits better classification performance than the original DCCA.
    Źródło:
    International Journal of Applied Mathematics and Computer Science; 2011, 21, 3; 549-558
    1641-876X
    2083-8492
    Pojawia się w:
    International Journal of Applied Mathematics and Computer Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Growth of NdBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-δ}$ Superconducting Thin Films on SrTiO$\text{}_{3}$(100) and LaSrGaO$\text{}_{4}$(100) Substrates
    Autorzy:
    Park, J.-C.
    Ha, D. H.
    Kim, I.-S.
    Park, Y.K.
    Powiązania:
    https://bibliotekanauki.pl/articles/1964239.pdf
    Data publikacji:
    1997-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    74.76.Bz
    Opis:
    NdBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-δ}$ superconducting thin films were grown on SrTiO$\text{}_{3}$(100) and LaSrGaO$\text{}_{4}$(100) substrates by off-axis rf sputtering and pulsed laser deposition. The effects of several deposition parameters, e.g. gas pressure, substrate temperature and energy density were studied. Thin films grown by off-axis rf sputtering were highly c-axis oriented, but those by pulsed laser deposition were predominantly a-axis oriented under our deposition conditions. However, the c-axis oriented portion for the films grown by pulsed laser deposition was increased by increasing the temperature above 800°C. T$\text{}_{c(zero)}$ was 87 K and 83 K for the c- and a-axis oriented films respectively. The critical current density of c-axis oriented films was 10$\text{}^{6}$-10$\text{}^{7}$ A/cm$\text{}^{2}$ below 60 K.
    Źródło:
    Acta Physica Polonica A; 1997, 92, 1; 105-114
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Compositional Dependence of Hardness of Ge-Sb-Se Glass for Molded Lens Applications
    Zależność stężeniowa twardości szkła Ge-Sb-Se do zastosowań na formowane soczewki
    Autorzy:
    Park, J. K.
    Lee, J. H.
    Shin, S. Y.
    Yi, J. H.
    Lee, W. H.
    Park, B. J.
    Choi, J. H.
    Kim, N. Y.
    Choi, Y. G.
    Powiązania:
    https://bibliotekanauki.pl/articles/352228.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    chalcogenide glasses
    Ge-Sb-Se glass
    infrared lens
    molded lens
    infrared camera
    szkło
    Ge-Sb-Se
    soczewki formowane
    twardość szkła
    kamera termowizyjna
    Opis:
    Chalcogenide glass in the ternary Ge-Sb-Se system is inherently moldable, thus being considered as a strong candidate material for use in infrared-transmitting lens applications from the viewpoint of thermal and mechanical stability. In an effort to experimentally determine compositional region suitable for the molded lens applications, we evaluate its compositional dependence of hardness. Among the constituent atoms, Ge content turns out to exert a most conspicuous correlation with hardness. This phenomenological behavior is then explained in connection with the structural evolution that Ge brings about.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1205-1208
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The High Temperature Oxidation Stability of STS434L/Silicon Oxide Compacts
    Autorzy:
    Park, J. W.
    Ko, B. H.
    Jung, W. Y.
    Park, D. K.
    Ahn, I. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/352481.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    high-temperature oxidation stability
    metallic oxide
    densification
    Opis:
    In order to improve the high-temperature oxidation stability, a study of 434L sintered stainless steel was focused on the effect of addition of metallic oxides to form stable oxide film on the inner particle surface. In this paper, oxidation behavior of 434L compacted parts in accordance with the addition of metallic oxides were discussed with high temperature oxidative reaction, and sintering behavior analysis under 950°C. Oxidation weight gains of 434 L have increased as a form of parabolic laws. The hightemperature oxidation resistance was improved by the mixed addition of amorphous SiO2 and silica up to 2wt.%. The oxidation rate was decreased and kept constant after 60 hours. It was caused by the restraint succeeding oxidation due to the stable oxide formation of Cr2SiO4 phases on the particle surface to prevent densification and inhibition the external diffusion of Cr. High-temperature stability was confirmed by the electrical resistivity maintains the constant value of 1.3×10-2 Ω ·cm when the silica added less than 2w/o to 1w/o A-SiO2 added 434L.
    Źródło:
    Archives of Metallurgy and Materials; 2018, 63, 1; 307-313
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fabrication of Mo-Si-B Intermetallic Compound Powders Under Different Heat Treatment Conditions
    Autorzy:
    Park, J. H.
    Lee, S.
    Kim, D.
    Kim, Y.
    Yang, S. H.
    Lee, S. H.
    Powiązania:
    https://bibliotekanauki.pl/articles/353369.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Mo-Si-B alloys
    intermetallic compounds
    reitveld refinement
    T2 phase
    A15 phase
    Opis:
    In this research, we investigated the effects of reduction atmospheres on the creation of the Mo-Si-B intermetallic compounds (IMC) during the heat treatments. For outstanding anti-oxidation and elevated mechanical strength at the ultrahigh temperature, we fabricated the uniformly dispersed IMC powders such as Mo5SiB2 (T2) and Mo3Si (A15) phases using the two steps of chemical reactions. Especially, in the second procedure, we studied the influence of the atmospheres (e.g. vacuum, argon, and hydrogen) on the synthesis of IMCs during the reduction. Furthermore, the newly produced IMCs were observed by SEM, XRD, and EDS to identify the phase of the compounds. We also calculated an amount of IMCs in the reduced powders depending on the atmosphere using the Reitveld refinement method. Consequently, it is found that hydrogen atmosphere was suitable for fabrication of IMC without other IMC phases.
    Źródło:
    Archives of Metallurgy and Materials; 2018, 63, 3; 1509-1512
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sintering and Microstructures of SUS 316L Powder Produced by 3D Printing Process
    Autorzy:
    Kim, W. J.
    Nguyen, H.-H.
    Kim, H. Y.
    Nguyen, M.-T.
    Park, H. S.
    Kim, J.-C.
    Powiązania:
    https://bibliotekanauki.pl/articles/356018.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    stainless steel
    3D printing
    selective laser sintering
    SUS 316L
    flake powder
    Opis:
    Selective laser sintering (SLS) is a type of laminating sintering technique, using CO2 laser with (metal, polymer, and ceramic) powders. In this result, the flake SUS 316L was used to achieve a high porous product, and compare to spherical type. After SLS, the porosity of flake-type sample with 34% was quite higher than that of the spherical-type one that had only 11%. The surface roughness of the flake SLS sample were also investigated in both inner and surface parts. The results show that the deviation of the roughness of the surface part is about 64.40μm, while that of the internal one was about 117.65μm, which presents the containing of high porosity in the uneven surfaces. With the process using spherical powder, the sample was quite dense, however, some initial particles still remained as a result of less energy received at the beneath of the processing layer.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1215-1218
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    High Temperature Oxidation Property of SiC Coating Layer Fabricated by Aerosol Deposition Process
    Autorzy:
    Ham, G.-S.
    Kim, S.-H.
    Park, J.-Y.
    Lee, K.-A.
    Powiązania:
    https://bibliotekanauki.pl/articles/352142.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    silicon carbide
    aerosol deposition
    coating
    high temperature oxidation
    Opis:
    This study investigated the high temperature oxidation property of SiC coated layer fabricated by aerosol deposition process. SiC coated layer could be successfully manufactured by using pure SiC powders and aerosol deposition on the Zr based alloy in an optimal process condition. The thickness of manufactured SiC coated layer was measured about 5 μm, and coating layer represented high density structure. SiC coated layer consisted of α-SiC and β-SiC phases, the same as the initial powder. The initial powder was shown to have been crushed to the extent and was deposited in the form of extremely fine particles. To examine the high temperature oxidation properties, oxidized weight gain was obtained for one hour at 1000°C by using TGA. The SiC coated layer showed superior oxidation resistance property than that of Zr alloy (substrate). The high temperature oxidation mechanism of SiC coated layer on Zr alloy was suggested. And then, the application of aerosol deposited SiC coated layer was also discussed.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1347-1351
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Range resolution improvement of range-gated vision system in backscattering hazy environments
    Autorzy:
    Park, S.-K.
    Choi, I.-Y.
    Baik, S.-H.
    Jeong, K.-M.
    Powiązania:
    https://bibliotekanauki.pl/articles/174523.pdf
    Data publikacji:
    2017
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    range-gated vision system
    range image
    windowed center-of-mass
    cross-correlation
    Gaussian window
    Opis:
    A range-gated vision system simultaneously provides two-dimensional and range images because its light intensity contains the reflectance as well as depth information. The range-resolution of the system is usually inversely proportional to the induced backscattering noise. In this paper, a range imaging technique is proposed to precisely measure range information from highly backscattering foggy environments. A windowed center-of-mass position extracted from the peak area of a cross-correlation signal of two signals, a Gaussian window signal in reduced size and a range-gated signal according to distance, is adopted as the range depth. The proposed measuring technique provides more robust and more precise range information than conventional measuring techniques for hazy targets by virtue of the reduction of backscattering bias noise usually induced by airborne particles. The experimental results and the signal processing procedures to acquire precise range information from hazy targets are described in this paper.
    Źródło:
    Optica Applicata; 2017, 47, 4; 533-543
    0078-5466
    1899-7015
    Pojawia się w:
    Optica Applicata
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Microstructure and Compression Properties of Fe-Cr-B Alloy Manufactured using Laser Metal Deposition
    Autorzy:
    Joo, Y.-A.
    Yoon, T.-S.
    Park, S.-H.
    Lee, K.-A.
    Powiązania:
    https://bibliotekanauki.pl/articles/352075.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Fe-Cr-B composite
    laser Metal Deposition
    bulk type
    microstructure
    compressive properties
    Opis:
    Fe-Cr-B alloy is a material with precipitation of boride inside Fe matrix, and it features outstanding hardness and wear resistance properties. However, Fe-Cr-B alloy is a difficult material to process, making it difficult to use as a bulk type structure material which requires delicate shapes. This study attempted to manufacture Fe-Cr-B alloy using a 3D printing process, laser metal deposition. This study also investigated the microstructure, hardness and compression properties of the manufactured alloy. Phase analysis results is confirmed that α-Fe phase as matrix and (Cr, Fe)2B phase as reinforcement phase. In the case of (Cr, Fe)2B phase, differences were observed according to the sample location. While long, coarse, unidirectional needle-type boride phases (~11 μm thickness) were observed in the center area of the sample, relatively finer boride phases (~6 μm thickness) in random directions were observed in other areas. At room temperature compression test results confirmed that the sample had a compression strength is approximately 2.1 GPa, proving that the sample is a material with extremely high strength. Observation of the compression fracture surface identified intergranular fractures in areas with needle-type boride, and transgranular fractures in areas with random borides. Based on this results, this study also reviewed the deformation behavior of LMD Fe-Cr-B alloy in relation to its microstructures.
    Źródło:
    Archives of Metallurgy and Materials; 2018, 63, 3; 1459-1462
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Microstructure Evolution of Ni-Based ODS Superalloy Powders During Horizontal Rotary Ball Milling
    Autorzy:
    Lee, H.-E.
    Kim, Y. S.
    Park, J. K.
    Oh, S.-T.
    Powiązania:
    https://bibliotekanauki.pl/articles/355552.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    high energy ball milling
    Ni-base ODS superalloy
    particle and crystalline size
    microstructure
    Opis:
    Microstructure evolution of Ni-based oxide dispersion-strengthened alloy powders with milling time is investigated. The elemental powders having a nominal composition of Ni-15Cr-4.5Al-4W-2.5Ti-2Mo-2Ta-0.15Zr-1.1Y2O3 in wt % were ball-milled by using horizontal rotary ball milling with the change of milling velocity. Microstructure observation revealed that large aggregates were formed in the early stages of ball milling, and further milling to 5 h decreased particle size. The average crystalline size, estimated by the peak broadening of XRD, decreased from 28 nm to 15 nm with increasing milling time from 1 h to 5 h. SEM and EPMA analysis showed that the main elements of Ni and Cr were homogeneously distributed inside the powders after ball milling of 5 h.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1253-1255
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect Of Ti Powder Addition On The Fabrication Of TiO2 Nanopowders
    Wpływ dodatku nanoproszku Ti na zagęszczanie i spiekanie nanoproszków TiO2
    Autorzy:
    Raihanuzzaman, R. M.
    Park, H. Y.
    Ghomashchi, R.
    Kwon, T. H.
    Son, H.-T.
    Hong, S.-J.
    Powiązania:
    https://bibliotekanauki.pl/articles/353186.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    TiO2 nanopowder
    magnetic pulsed compaction
    densification
    sintering
    nanoproszek Ti
    magnetyczne zagęszczanie impulsowe
    zagęszczanie
    spiekanie
    Opis:
    Sintered samples of Ti added TiO2 nanopowders were fabricated by combined application of magnetic pulsed compaction (MPC) and sintering. The effect of Ti nano powder on density, shrinkage and hardness of the samples were investigated as part of the study. The optimum processing conditions were found to be around 0.5 GPa MPC pressure and 1450°C sintering temperature, illustrating maximum density, hardness and minimum shrinkage. High pressure compaction using MPC was found to enhance density with increasing MPC pressure up to 0.9 GPa, and significantly reduce the total shrinkage (about 16% in this case) in the sintered bulks compared to other general processes (about 18%). While sintered samples blended with micro Ti showed presence of microstructural cracks, the samples with 1-2% nano Ti had less or no cracks on them. Overall, the inclusion of nano Ti indicated improvement in mechanical properties of TiO2 nanopowders sintered preforms as opposed to micro Ti-added TiO2.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1473-1477
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Heat Treatment on Microstructure and Impact Toughness of Ti-6Al-4V Manufactured by Selective Laser Melting Process
    Autorzy:
    Lee, K.-A.
    Kim, Y.-K.
    Yu, J.-H.
    Park, S.-H.
    Kim, M.-C.
    Powiązania:
    https://bibliotekanauki.pl/articles/354570.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    selective laser melting
    Ti-6Al-4V
    microstructure
    impact toughness
    heat treatment
    Opis:
    This study manufactured Ti-6Al-4V alloy using one of the powder bed fusion 3D-printing processes, selective laser melting, and investigated the effect of heat treatment (650°C/3hrs) on microstructure and impact toughness of the material. Initial microstructural observation identified prior-β grain along the building direction before and after heat treatment. In addition, the material formed a fully martensite structure before heat treatment, and after heat treatment, α and β phase were formed simultaneously. Charpy impact tests were conducted. The average impact energy measured as 6.0 J before heat treatment, and after heat treatment, the average impact energy increased by approximately 20% to 7.3 J. Fracture surface observation after the impact test showed that both alloys had brittle characteristics on macro levels, but showed ductile fracture characteristics and dimples at micro levels.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1341-1346
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Study On The Electro-Refining Of Tin In Acid Solution From Electronic Waste
    Badanie elektrorafinacji cyny w roztworze kwasu z e-odpadów
    Autorzy:
    Son, S. H.
    Park, S. C.
    Kim, J. H.
    Kim, Y. H.
    Lee, M. S.
    Ahn, J.-W.
    Powiązania:
    https://bibliotekanauki.pl/articles/352665.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    electrorefining
    tin
    electronic waste
    recycling
    high purity
    elektrorafinacja
    cyna
    odpady elektroniczne
    recykling
    Opis:
    The tin metal could be retractable from wasted tin scrap, sludge, and wasted electroplated solution hydrometallurgical treatment, and purification process. In order to be used as resource of electronic devices, the retracted crude metal should be purified to the extent of higher than 99.9%. In this study, tin electro-refining process was performed to purify the casted tin crude metal at various experimental conditions: at the current density of 3, 5A/dm2, and in various electrolytes such as hydrochloric acid, sulfuric acid and methansulfonic acid. Additional experiment was conducted using Rotating Disk Electrode (RDE) in order to investigate the rate determining step of tin electro-refining process. The current efficiency, 65.6%, was achievable at the condition of current density, 5A/dm2, and in the electrolyte of Hydrochloric acid. During tin electro-refining process, impurity dissolved from tin crude metal into the electrolyte was analyzed using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES), and the result showed the concentration of impurity metal gradually increased. Quantitative analysis on casted tin crude metal showed that it consists of tin with 93.9 wt.% and several impurity metals of Ag, Bi, Pb, Cu, and etc. After tin electro-refining process, the purity of tin increased up to 99.985 wt.%.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1217-1220
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Isotopic water separation using AGMD and VEMD
    Autorzy:
    Kim, J.
    Park, S.
    Kim, T.-S.
    Jeong, D.-Y.
    Ko, K.-H.
    Powiązania:
    https://bibliotekanauki.pl/articles/147314.pdf
    Data publikacji:
    2004
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    AGMD
    VEMD
    oxygen isotopes
    PET
    FDG
    Opis:
    The 18O isotopic water permeation and separation characteristics of a hydrophobic PTFE membrane using Air Gap Membrane Distillation (AGMD) and Vacuum Enhanced Membrane Distillation (VEMD) were investigated. Permeation fluxes were measured by weighing the collected membrane-permeated water vapor. 18O/16O of each water sample was analyzed by the Tunable Diode Laser Absorption Spectroscopy (TDLAS). We observed the effects of the air filled membrane pores and the temperature gradient applied to the membrane surfaces on the vapor permeation flux and the oxygen isotope separation for the first time. For both AGMD and VEMD, the permeation flux and the degree of 18O separation increased as the membrane interfacial temperature gradient increased. Even though, oxygen isotope separation and the permeation flux for VEMD is slightly higher than AGMD, the latter may be more efficient from the system's operational point of view.
    Źródło:
    Nukleonika; 2004, 49, 4; 137-142
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Surface Characterization of Metallic Fuel Slugs Prepared by Modified Injection Casting
    Autorzy:
    Mun, S.-U.
    Kim, K.-H.
    Oh, S.-J.
    Park, J.-Y.
    Hong, S.-I.
    Powiązania:
    https://bibliotekanauki.pl/articles/351428.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    sodium-cooled fast reactor
    metallic fuel slug
    U-Zr alloy
    surface characterization
    injection casting
    Opis:
    Metallic fuel slugs containing rare-earth (RE) elements have high reactivity with quartz (SiO2) molds, and a reaction layer with a considerable thickness is formed at the surface of metallic fuel slugs. The surface characterization of metallic fuel slugs is essential for safety while operating a fast reactor at elevated temperature. Hence, it is necessary to evaluate the surface characteristics of the fuel slugs so that chemical interaction between fuel slug and cladding can be minimized in the reactor. When the Si element causes a eutectic reaction with the cladding, it deteriorates the metallic fuel slugs. Thus, it is necessary to examine the characteristics of the surface reaction layer to prevent the reaction of the metallic fuel slugs. In this study, we investigated the metallurgical characteristics of the surface reaction layer of fabricated U-10wt.%Zr-Xwt.%RE (X = 0, 5, 10) fuel slugs using injection casting. The results showed that the thickness of the surface reaction layer increased as the RE content of the metallic fuel slugs increased. The surface reaction layer of the metallic fuel slug was mainly formed by RE, Zr and the Si, which diffused in the quartz mold.
    Źródło:
    Archives of Metallurgy and Materials; 2018, 63, 2; 1049-1053
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Characterization of Cladding Hull Wastes from Used Nuclear Fuels
    Charakterystyka odpadów z okładzin reaktora wodnego ciśnieniowego
    Autorzy:
    Kang, K. H.
    Lee, C. H.
    Jeon, M. K.
    Han, S. Y.
    Park, G. I.
    Hwang, S.-M.
    Powiązania:
    https://bibliotekanauki.pl/articles/357036.pdf
    Data publikacji:
    2015
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    used nuclear fuels
    metal waste
    cladding hulls
    zircaloy
    radioactivity
    reaktor wodny ciśnieniowy
    odpady metalowe
    odpady z okładzin
    radioaktywność
    Opis:
    Used cladding hulls from pressurized water reactor (PWR) are characterized to provide useful information for the treatment and disposal of cladding hull wastes. The radioactivity and the mass of gamma emitting nuclides increases with an increase in the fuel burn-up and their removal ratios are found to be more than 99 wt.% except Co-60 and Cs-137. In the result of measuring the concentrations of U and Pu included in the cladding hull wastes, most of the residues are remained on the surface and the removal ratio of U and Pu are revealed to be over 99.98 wt.% for the fuel burn-up of 35,000 MWd/tU. An electron probe micro-analyzer (EPMA) line scanning shows that radioactive fission products are penetrated into the Zr oxide layer, which is proportional to the fuel burn-up. The oxidative decladding process exhibits more efficient removal ratio of radionuclides.
    Źródło:
    Archives of Metallurgy and Materials; 2015, 60, 2B; 1199-1203
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fabrication of High-Strength Gray Cast Iron Using Permanent Magnet Scrap
    Autorzy:
    Park, S.-Y.
    Kim, J. H.
    Seo, S. J.
    On, J. S.
    Lim, K. M.
    Powiązania:
    https://bibliotekanauki.pl/articles/352204.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    gray cast iron
    rare earth element
    Nd-Fe-B magnet scrap
    graphite formation
    microstructure
    Opis:
    In this study, we have developed the manufacturing technology for high strength gray cast irons by using the spent permanent magnet scraps. The cast specimen inoculated by using a spent magnet scraps showed the excellent tensile strength up to 306MPa. This tensile strength value is 50MPa higher than that of the specimen cast without inoculation, and is similar to that of the specimen inoculated by using the expensive misch-metal. These superior mechanical properties are attributed to complex sulfides created during solidification that promote the formation and growth of Type-A graphite. It is therefore concluded that spent magnets scrap can provide an efficient and cost-effective inoculation agent for the fabrication of high-performance gray cast iron.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1113-1117
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Diets supplemented with Mytilus galloprovincialis from polluted and non-polluted waters and their influence on zinc content in liver of rats loaded with cholesterol
    Diety z dodatkiem Mytilus galloprovincialis z wód niezanieczyszczonych i zanieczyszczonych oraz ich wpływ na zawartość cynku w wątrobie szczurów obciążonych cholesterolem
    Autorzy:
    Jesion, I.
    Leontowicz, M.
    Leontowicz, H.
    Kolnierzak, M.
    Gralak, M.A.
    Park, Y.-S.
    Gorinstein, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2958.pdf
    Data publikacji:
    2014
    Wydawca:
    Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
    Tematy:
    animal diet
    diet supplementation
    Mytilus galloprovincialis
    mussel
    polluted water
    non-polluted water
    zinc content
    liver
    rat
    cholesterol
    Opis:
    Diets supplemented with Mytilus galloprovincialis from polluted and non-polluted waters and their influence on zinc content in liver of rats loaded with cholesterol. Mussels may reflect the environmental problems that the ecosystem faces. Mytilus galloprovincialis is widely used as an indicator of water pollution in biological monitoring studies. These mussels are filter feeders and may accumulate important ecosystem pollutants what in turn may pose a potential risk to other organisms in the food chain. The aim of the study was to determine zinc content in the diets supplemented with mussels from polluted and non-polluted areas and in the livers of rats fed these diets for 30 days. The zinc content in the diets with mussels from contaminated and noncontaminated waters and in rat livers was examined using a flame atomic absorption spectrophotometry (Perkin-Elmer 1100B). The slight increase in zinc content from 73.2 ±1.2 mg/ /kg in ch diet (control with 1% of cholesterol) to 77.2 ±0.5 mg/kg in the diet with mussels from polluted site was found, but zinc content in all diet was within the normal limits reviewed by McDowell (1992) – 40 to 100 ppm. Zinc content in the diet supplemented with mussels from nonpolluted site (73.7 ±3.7 mg/kg) was similar to that found in ch diet. It can be concluded that cholesterol does not affect zinc bioaccumulation. However, prolonged consumption of mussels from contaminated sites may increase accumulation of zinc in the liver of rats.
    Diety z dodatkiem Mytilus galloprovincialis z wód niezanieczyszczonych i zanieczyszczonych oraz ich wpływ na zawartość cynku w wątrobie szczurów obciążonych cholesterolem. Małże mogą odzwierciedlać problemy środowiskowe, przed którymi stoi ekosystem. Mytilus galloprovincialis jest szeroko wykorzystywany w biomonitoringu. Małże te są filtratorami i mogą kumulować w tkankach ważne zanieczyszczenia z ekosystemu, co z kolei może stanowić potencjalne zagrożenie dla innych organizmów w łańcuchu troficznym. Celem badania było określenie zawartości cynku w dietach z dodatkiem małży z obszarów niezanieczyszczonych i zanieczyszczonych oraz w wątrobach szczurów żywionych tymi dietami przez 30 dni. Zawartość cynku w dietach z małżami z zanieczyszczonych i niezanieczyszczonych wód i wątrobach szczurów oznaczono metodą płomieniowej absorpcji atomowej (Perkin-Elmer 1100B). Wykazano nieznaczny wzrost zawartości cynku w diecie z małżami z wód zanieczyszczonych (77,2 ±0,5 mg/kg) względem grupy ch – kontrola z 1% udziałem cholesterolu (73,2 ±1,2 mg/kg), ale zawartość cynku we wszystkich dietach mieściła się w granicach normy podanych przez McDowell (1992) – 40–100 ppm. Zawartość cynku w diecie z małżami z obszarów niezanieczyszczonych (73,7 ±3,7 mg/kg) była zbliżona do zawartości w diecie grupy ch. Podsumowując wyniki, można stwierdzić, że cholesterol nie wpływa na bioakumulację cynku. Jednak, długotrwałe spożywanie małży z wód zanieczyszczonych może zwiększyć akumulację cynku w wątrobie szczurów.
    Źródło:
    Annals of Warsaw University of Life Sciences - SGGW. Animal Science; 2014, 53
    1898-8830
    Pojawia się w:
    Annals of Warsaw University of Life Sciences - SGGW. Animal Science
    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:
    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
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