• Journal of Korea Foundry Society
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• v.29 no.5
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• pp.198-203
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• 2009

In order to manufacture copper ultra fine wire used for bonding wire in integrated circuit package, continuous casting process, which can produce high purity copper rod with small cross section, and wiredrawing process have to be optimized to prevent wire brakeage during entire manufacturing process of fine wire. The optimum condition for producing copper rod with mirror surface has to established by investigation of the effects of several parameters such as withdrawal speed, superheat and rod diameter on grain morphology of the cast rod and on its drawing characteristics to fine wire. The purpose of this study is to propose the optimized process parameters in continuous casting process in order to produce cast rod without internal defects, and to predict microstructure orientation suitable for wire drawing process.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.11
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• pp.1651-1657
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• 2015

In MHz operating wireless power transfer systems, skin- and proximity-effect losses in the transmitter and the receiver coils dominate the coil-to-coil efficiency of the system. A Litz-wire was regarded as a common solution for minimizing such Ohmic losses in high frequencies. In this paper, equivalent series resistances of 12 different cables including Litz-wire and copper tubing have been calculated and measured for a 6.78 MHz, 100W, 30 cm wireless power transfer system. It has been shown that the copper tubing has lower resistances compared to the Litz-wire in that frequency and a wireless power transfer system with the copper tubing was able to achieve much higher efficiency than a system using the Litz-wire. Calculations of the resistances and efficiencies were accomplished with analytical equations and those calculations were evaluated by experimental results.

• Korean Journal of Animal Reproduction
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• v.12 no.2
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• pp.84-90
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• 1988

This study was done with mouse embryos to determine effects of the freezing media with or without 10% sucrose, and seeding methods (pincette, no seeding, liquid nitrogen gas phase and copper wire coiled straw) on embryo survival were determined using the FDA test. The summarized results are the following. 1. The FDA score found with copper wire coiled straw, no seeding, pincette and liquid nitrogen gas phase was 3.6, 3.6, 3.3 and 3.0, respectively. There were no significant differences. 2. The embryo score shows higher (P<0.05) survival rate using a freezing medium with sucrose than the one without it. Among the seeding procedure, better resutls are copper wire coiled straw and no seeded. 3. The results suggest that copper wire coiled seeding no seeding be as good as seeding when the mouse embryos were frozen in a liquid nitrogen container using both the freezing and dilution media containing 10% sucrose.

• Proceedings of the KWS Conference
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• v.43
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• pp.237-239
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• 2004

• Journal of Korea Foundry Society
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• v.33 no.6
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• pp.248-253
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• 2013

To add alloying elements into a pure copper melt, the wire-feeding efficiency of cored (alloy containing) wire was evaluated using a commercial, computational fluid-dynamics program. The model design was based on an industrial-scale production line. The variables calculated included wire feed rate, melt temperature, wire diameter, melt flow rate and wire temperature. Efficiency was evaluated after a series of calculations based on the penetration depth of the alloy-wire into the molten copper bath. Of the five variables investigated, the wire feed rate and wire diameter were the most influential factors affecting the feeding efficiency of the cored-wire.

• Journal of Fashion Business
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• v.11 no.1
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• pp.38-47
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• 2007

In the modern society that is advancing rapidly, the hair art is also advancing and subdividing. The purpose of this study is to investigate unique field of formative as characteristics and forms of copper wire, focused on such a harmony of hair art, the present thesis aims at developing concept of hair art as a creative way, and recognizing the formative characteristics of copper wire as analyze and arrange the concept of hair art, formative, a way of practical application, material aspect, through literature, academic journals, photo data, and researched about prior piece, for example, architecture and costume with hair art, and then pieces of hair art were made. Influenced by the theory, applied the social phenomenon and the formative principles, produced the five pieces which includes balance, composure, flying, harmony, way, spring etc. The results of this research are outlined below. Firstly, It showed that the copper wire can express the mysterious and beautiful formative world, and it could know the possibility of design. Secondly, formative activity using copper wire can differ according to approach and interpretation, and it can be a works with aesthetic value. Thirdly, hair could be express the art of the three-dimensional forms which constitute the mixture of line, surface and space. So, hair art has enlarged the fields with development of technique, and changed to recognition of the hair art, and opened up a new field. Hair art will be positive fields to maximize the possibility, and not only the beauty artist but also the public will be communicate each other.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.11a
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• pp.55-62
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• 2001

An electrolytic copper rod was drawn up to $90\%$ in area reduction and annealed under various conditions. The EBSD measurement of the drawn wire showed that in the center region the <111> + <100> fiber duplex texture was dominant, while in the middle and surface regions relatively defused textures developed with a little higher density in <11w>//wire axis. The inhomogeneous texture in the deformed wire gave rise to the inhomogeneous microstructure and texture after annealing. The annealing texture could be classified into the recrystallization texture developed during low temperatures and at the early stage at a high temperature and the growth texture developed after a prolonged annealing at the high temperature. The recrystallization temperature could be explained by the strain energy release maximization model and the growth texture was discussed based on the grain boundary mobility anisotropy.

• Fire Science and Engineering
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• v.22 no.5
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• pp.43-47
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• 2008

Recently SIMS has attracted interest as new technique to distinguish the primary and the secondary arc beads. A Cs+ primary ion beam was used to detect the $^{12}C^-$, $^{63}Cu^-$, $^{18}O^-$, $^{35}Cl^-$ secondary ions which are formed during depth profiles in the copper wires. In this work, we studied thermal diffusion in the copper wire which are occurred with supplying over-current. The results demonstrated that Carbon and Chloride are diffused in PVC-coated copper wire deeper than none PVC-coated. However Oxygen showed the reverse diffusion property.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.554-555
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• 2005

In this paper, we analyzed a metallurgical structure and arc properties of copper wire when the over-current flows on electric wire. From the results, The fusing current was related to the fusing time(current rising rate per second). In case of the shorter the fusing time, the fusing current was high, and the fusing time of ac type was larger than that of dc type. The copper wire was bent by the increase of current and heated, the beads were scattered around wire with a flash. We could observed the dendrite structure in 'molten wire at ac and dc current type. According as the current rising rate per second is short, the dendrite structure is distributed in surface of wire.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.3
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• pp.52-58
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• 2008

The importance of. identifying the causes of electrical faults cannot be overstated because of the accidents caused by over-current that take place at the home, the office and electrical facilities due to misuse, poor products and system faults. It is necessary to gather objective, scientific data pertaining to electrical fault investigation in a product liability(PL) environment. To date, no database(DB) has been built concerning the accurate cause analysis of faultyfacilities. In this paper, accident hazard and arc scattering when over-current flows in copper wire was investigated. It was found that when over-current flows in a copper wire, the copper wire became heated and bent and beads were scattered around the wire with a flash. It was determinedthat the fusing current and time was related to the current rise per second. For example, when the current rise per second was largethe fusing current was higher than when the current rise per second was small, and the beads dispersed along a wide area. Fusing time, however, was shorter. The possibility of electrical fault became highest when the fusing current was higher. As the current rise per second is short, the dendrite structure is distributed in the surface of the copper wire. These experimental results can be utilized for a fault process DB system in the investigation and the prevention of electrical faults.