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CORROSION AND MECHANICAL BEHAVIOR OF COPPER-NIOBIUM NANO-FILAMENTARY MICRO-COMPOSITES FOR HIGH PERFORMANCE ELECTRICAL CONDUCTOR WIRE

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Acta Metallurgica Sinica(English Letters) 2002年第2期15卷 154-159页

作者： Y Choi1), T.W.Lim1) and S.I. Hong2) 1)department of Metallurgical engineering, Sunmoon university, Asan Chungnam 336-840, korea 2)department of Metallurgical engineering, Chungnam National university, Taedok Science Town, Daejeon 305-764,korea department of Metallurgical engineering Sunnioon University department of Metallurgical engineering Chungnam National University

Corrosion behavior of heavily drawn bundled Copper-niobium filamentarymicro-composite was studied as a function of niobium content to develop the relationship betweenmicrostructure and corrosion behavior in aqueous 30 percent HCl-FeCl_3 solution. TEM observationrevealed that niobium filaments were distributed regularly in copper matrix along the sides of atriangular unit cell in the transverse section and more sub-grain boundaries were absorbed atcopper/niobium phase boundaries with increasing niobium content. The corrosion potential and rate inaqueous 30 percent HCl-10 percent FeCl_3 was-680.3m V_(SHE) and 1.179 X 10^(-5)A/cm^2. Thecorrosion potential and rate decreased as increasing niobium content and FeCl_3. The yield stresscan be described as the sum of the substructure strengthening component due to elongated grains,subgrains and/or cells, the phase boundary strengthening term associated with the Hall-Petch typeinteraction between dislocations and phase boundaries and precipitate strengthening component.

关键词： Cu-Nb micro-composites corrosion microstructure

Quasimolecular Dynamic Simulation for Bending Fracture of Laminar Composite Materials

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Journal of Materials Science & Technology 2001年第5期17卷 547-552页

作者： Youngsuk Kim and Youngmoon Lee department of Mechanical engineering, Kyungpook National university, Taegu, South korea Dongyoul Choi and Chanil Kim Graduate School, Kyungpook National university, Taegu, South korea Kyungpook Natl Univ Dept Mech Engn Taegu 702701 South Korea Kyungpook Natl Univ Grad Sch Taegu 702701 South Korea

Recently, quasimolecular dynamics has been successfully used to simulate the deformation characteristics of actual size solid materials. In quasimolecular dynamics, which is an attempt to bridge the gap between atomistic and continuum simulations, molecules are aggregated into large units, called quasimolecules, to evaluate large scale material behavior. In this paper, a 2-dimensional numerical simulation using quasimolecular dynamics was performed to investigate laminar composite material fractures and crack propagation behavior in the uniform bending of laminar composite materials. It was verified that under bending deformation laminar composite materials deform quite differently from homogeneous materials

关键词： Quasimolecular Dynamic Simulation for Bending Fracture of Laminar Composite Materials Simulation

EFFECTS　OF　TEMPERATURE　ON　DISTRIBUTION　BEHAVIORS　OF　MINOR　ELEMENTS　IN　COPPER　FLASH　SMELTING──COMPUTER　SIMULATION

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中国有色金属学会会刊：英文版 1996年第4期6卷 38-41页

作者： Tan Pengfu Zhang Chuanfu(department of Nonferrous Metallurgy,Central South university of Technology,Changsha 410083) Tong Rae Cho(department of Metallurgical engineering,Chungnam National university,South korea) CHUNGNAM NATL UNIV DEPT ENGN METTAEJONSOUTH KOREA CENT S UNIV TECHNOL DEPT NONFERROUS METCHANGSHA 410083PEOPLES R CHINA

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关键词： As Sb Bi Pb Zn simulation computer model thermodynamics

Formation and Morphology of Anodic Oxide Films of Ti

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Journal of Materials Science & Technology 2001年第1期17卷 33-34页

作者： Kyo-Han Kim X.L.Zhu and Won-Woo Son department of Dental Biomaterials, Kyungpook National university, Taegu 700-422, korea Yong-Soo Jeong department of Surface engineering, korea institute of Machinery and Materials, Changwon, korea Kyungpook Natl Univ Dept Dent Biomat Taegu 700422 South Korea korea Inst Machinery & Mat Dept Surface Engn Changwon South Korea

The morphology and structure of the oxide films of Ti in H3PO4 were investigated by galvanos tatic anodization, SEM and XRD. The oxide film grew from some pores in the grooves to layered microdomains as increasing anodizing voltage. The crystallinity of the oxide films decreased with the increase of the concentration of the electrolyte. The model has been proposed for the growth of the oxide films by two steps, i.e. by uniform thickening and by local deposition.

关键词： Res Formation and Morphology of Anodic Oxide Films of Ti

MODELING ON THE CYCLIC OPERATION OF STANDING COLUMN WELLS UNDER REGIONAL GROUNDWATER FLOW

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Journal of Hydrodynamics 2011年第3期23卷 295-301页

作者： LEE Kun Sang department of Natural Resources and Environmental engineering Hanyang university

Coupled hydrogeological-thermal simulation of the Standing Column Well （SCW） system is essential to provide an optimized configuration and operation schedule for boreholes on the site. This paper presents numerical investigations and thermo-hydraulic evaluation of standing column well system operating under cyclic flow regime. A three-dimensional numerical model for groundwater flow and heat transport is used to analyze the heat exchange in the ground. The model includes the effects of convective and conductive heat transfer, heat loss to the adjacent confining strata, and hydraulic anisotropy. The operation scenario consists of cyclic injection and recovery and four periods per year to simulate the seasonal temperature conditions. For different parameters of the system, performances have been evaluated in terms of variations in recovery temperature. The calculated temperatures at the producing pipe are relatively constant within a certain range through the year and fluctuating quarterly a year. Pipe-to-pipe distance, injection/production rate, ground thickness, and permeability considered in the model are shown to impact the predicted temperature profiles at each stage and the recovery water temperature. The influence of pressure gradient, which determines the velocity of regional groundwater flow, is most substantial.

关键词： standing column well thermo-hydraulic evaluation cyclic regime numerical simulation

THE INFLUENCES OF Zn CONTENT AND COOLING RATE ON ASCAST MICROSTRUCTURE IN Al75% Mg ALLOYS

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Acta Metallurgica Sinica(English Letters) 1999年第4期12卷 521-527页

作者： Q.Wu1)and S.B.Kang2) 1) department of Material Science and engineering, Nanjing university of Science and Technology , Nanjing,210014 ,China 2) department of Material engineering ,korea Institute of Mechanics and Materials,Changwon , korea

Thesolidification processof Al 7 5% Mg Zn alloys wasstudiedin *** Zn contentand cooling rate werechanged andtheirinfluenceson as cast microstructure were measured by different methods. The solute segregation during nonequilibrium solidification process wascalculated byternary Scheilequation which wasin good agreement with experimentresulte.

关键词： aluminum alloy as cast microstructure nonequilibrium solidification

Effect of Cross-linking Agent on Barbituric Acid-initiated Resin

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Journal of Materials Science & Technology 2001年第1期17卷 27-28页

作者： Eun-Kyung Lee Hwan-Wook Ra and Kyo-Han Kim department of Dental Biomaterials, College of Dentistry, Kyungpook National university, Taegu 700-422, korea Inn-Kyu Kang department of Polymer engineering, College of engineering, Kyungpook National university, Kyungpook Natl Univ Coll Dent Dept Dent Biomat Taegu 700422 South Korea Kyungpook Natl Univ Coll Engn Dept Polymer Engn Taegu 700422 South Korea

To improve the tensile bond strength of denim bonding agents, the adhesion between denim and MMA resin was investigated by applying initiator systems containing 1-cyclohexyl-5-ethyl barbituric acid (CEB), copper acetyl acetonate (CAA), quaternary ammonium chloride (QAC). cupric ion, with the addition of TEGDMA, an.d pretreatment solution for denim, and an HEMA primer. The effects of a cross-linking agent on barbituric acid-initiated denim bonding resin were examined by measuring degree of conversion, molecular weight, hardness of bonding resin, and tensile bond strengths.

关键词： Figure Effect of Cross-linking Agent on Barbituric Acid-initiated Resin FTIR

Fabrication, microstructure and properties of SiCp/Cu heat sink materials

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Rare Metals 2006年第z2期25卷 232-236页

作者： KANG Suk-bong korea Institute of Machinery and Materials 66 Sangnam-dong Changwon 641-010 Korea

Cu-coated powder was fabricated by electroless plating process, and the composition and morphology of coated powder were studied. Moreover, Cu-30, 40, 50 vol.%SiCp heat sink materials were fabricated by hot pressing using coated and uncoated powder. And the microstructure and thermophysical properties of the heat sink materials were also studied. The results show that SiCp particles distribute uniformly in heat sink materials and the interface between SiCp particles and Cu matrix is clear and well bonded. On the condition of same volume fraction of SiCp, the thermal conductivity of the material using coated powder is larger than that of the material using uncoated powder. Under experiment conditions, the thermal conductivity and coefficient of thermal expansion of Cu-30 vol.%SiCp heat sink material is 236.2 W·m-1·K-1 and 9.9×10-6/K (30-200 ℃) respectively. It provides important reference data for future experiments.

关键词： heat sink material electroless copper plating coefficient of thermal expansion thermal conductivity

PRECIPITATION HARDENING IN B2-ORDERED NiAl BY Ni_(2)AlTi COMPOUND

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Acta Metallurgica Sinica(English Letters) 2001年第5期14卷 313-318页

作者： W.H. Tian, K. Ohishi and M. Nemoto 1)department of Materials Physics and Chemistry, university of Science and Technology Beijing, Beijing 100083, China 2)department of Materials Science and engineering, Faculty of engineering 36, Kyushu university, Fuk Dept. of Mat. Phys. and Eng. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Microstructural variations and correlated hardness changes in B2-ordered NiAl containing fine precipitation of Ni2AlTi have been investigated by means of transmission electron microscopy (TEM) and hardness tests. The amount of age hardening is not large as compared to the large microstructural variations during aging. TEM observations have revealed that the L21-type Ni2AlTi precipitates keep a lattice coherency with the NiAl matrix at the beginning of aging. By longer periods of aging Ni2AlTi precipitates lose their coherency and change their morphology to the globular ones surrounded by misfit dislocations. The temperature dependence of the yield strength of precipitate-containing B2-ordered NiAl was investigated by compression tests over the temperature range of 873-1273 K. The fine precipitation of Ni2AlTi was found to enhance greatly the yield strength and the high-temperature strength is comparable with that of superalloy Mar-M200.

关键词： Aluminum Hardening Mechanical properties Nickel Precipitation (chemical)