• Journal of the Korean Society for Precision Engineering
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• v.32 no.10
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• pp.891-896
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• 2015

In order to protect the environment, using light material is becoming more and more attractive within the automobile industry. Aluminum alloys are the best and lightest metallic materials used in the automotive, electron, and aerospace industries. Al alloy and SGARC were joined by cold metal transfer (CMT) welding, using AlSiMn4 as a filler. Results showed that dissimilar metals from the Al 6000 series/SGARC could be successfully joined by CMT under proper processing parameters. The micro-hardness value of 125Hv was obtained at an interface.

• Journal of Welding and Joining
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• v.13 no.1
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• pp.145-155
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• 1995

Continuous wave C $O_{2}$ laser beam welding and formability of zinc coated steel plates were investigated. First, the optimal welding condition could be obtained in lap configuration by using the data for heat input, gap size and fracture behaviour. The gap size for fully-penetrated bead could be predicted by the gap model by Akhter et al. AIso, it was found that the joining efficiency was constant. Secondly, the butt welding of dissimilar materials (zinc coated steel plate and cold rolled steel plate) with different thicknesses was investigated. In the thickness range of 0.8-2.0 mm, the maximum welding speed of 10m/min was obtained. In the butt welding of two plates with thickness 2.0 mm and l.6mm, the maximum, welding speed of 6m/min was obtained, Finally. the forming results of butt-welded plates showed that the joining design was important to apply the laser welded blank in the automotive production.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.1
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• pp.3-8
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• 2012

In an attempt to improve adhesion strength between glass and metal due to use of Pb-free solder as a sealant between glass and metal in the manufacturing process of vacuum insulation window glass to maintain the vacuum volume, ultrasonic energy is often applied during the process of Pb-free sealing. In this study, we propose an ultrasonic vibrator with a 4 mm end tip radius which performs resonance frequency of 60 kHz and 14 um or higher vibration displacement. A frequency variation due to applied pressure on piezo disks, which was excluded in the computer simulation, was verified experimentally, and we have demonstrated a 17 um vibration displacement at 50 V input through the performance test of a vibrator constructed with our specification.

• Textile Coloration and Finishing
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• v.18 no.5 s.90
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• pp.61-71
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• 2006

This paper addresses the factors hindering the image quality of lines in inkjet printed on polyester fabric as printing media. Lines were printed onto different types of polyester fabrics in warp and filling directions. Line image quality including line width, edge blurriness, and edge raggedness was assessed. The effect of capillary wicking on line image quality of printed spun polyester fabric is discussed. The factors on the image quality include printing position(top of the yam or between the yarn), printing direction(warp or filling), yarn structures(filament or spun), thread size(yam or fiber), finishing, and ink properties(evaporation rate). More than 30% differences in image quality results were observed by changing the printing location on the spun polyester fabric. The best results of the image quality were obtained with the printed plain and spun polyester fabrics. The fiber sizes may affect capillary size; therefore, the image quality can be dissimilar. Types of finishing materials and inks greatly improve the line image quality on spun polyester fabrics.

• Transactions of Materials Processing
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• v.20 no.1
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• pp.64-72
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• 2011

In this study, we have investigated bonding of metal and plastic parts with single planar interface. This is facilitated by surface processing of aluminum sheet, which consists of slitting and punching, followed by insert-molding of polybuthylelne terephthalate(PBT). An injection mold has been built to fabricate specimen. After processing of the specimen, tensile and bending shear adhesion tests have been fulfilled according to KS M3734 and KS M3723, respectively. We also have conducted simulation of tensile and bending shear adhesion tests. Based on the tests results, the proposed bonding method outperforms existing methods based on adhesion.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.6
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• pp.1108-1114
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• 1992

In this paper results from experimental studies on the line wave detonation of explosive welding were presented. Using the ultra high speed comera, the ling wave generation during the bonding, process of composite materials was observed with an equilateral triangle lens. Experimental results confirmed the line wave formation of the shock front. And the results indicated the effectiveness of the ling wave detonation method in the explosive welding of similar or dissimilar metals.

• Journal of the Korean Society of Industry Convergence
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• v.3 no.1
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• pp.69-75
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• 2000

Multichip packages are comprised of dissimilar materials which expand at different rates on heating. The differential expansion must be accommodated by the various structural elements of the package. A types of heat exposures occur operation cycles. This study presents a finite element analysis simulation of flip-chip among multichip. The effects of geometries and material properties on the reliability were estimated during the analysis of temperature and thermal stress of flip-chip. From the results, it could be obtained that the more significant parameters to the reliability of flip-chip arc chip power cycle, heat convection and height of solder bump.

• Journal of Powder Materials
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• v.4 no.4
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• pp.252-257
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• 1997

Cu-brazed layer between the sintered-cam(Fe-5Cr-lMo-0.5P-2.5C, wt%) and seamless steelpipe(0.25-0.35C, 0.3-1.0 Mn, bal Fe, wt%) in the camshaft shows a columnar structure of $\gamma$-phase growing from the steel pipe. Liquid phase sintered 60Fe-40Cu alloys are carburized to simulate the brazing process giving rise to the columnar growth. Liquid film migrations and columnar growth of $\gamma$-grains are observed in the carburized regions. The $\gamma$-grains grow in the same direction as the C-diffusion. Fe-solubility in the liquid of carburized region is higher than in the uncarburized by about 0.3 at%. The columnar growth is driven by the gradient of the supersaturated Fe-solute in the liquid between two adjacent $\gamma$-grains.

• Structural Engineering and Mechanics
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• v.36 no.1
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• pp.95-110
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• 2010

Two-dimensional elastic contact problems, including normal, tangential, and rolling contacts, are treated with the finite element method in this study. Stress boundary conditions and kinematic conditions are transformed into multiple point constraints for nodal displacements in the finite element method. Upon imposing these constraints into the finite element system equations, the calculated nodal stresses and nodal displacements satisfy stress and displacement contact conditions exactly. Frictional and frictionless contacts between elastically identical as well as elastically dissimilar materials are treated in this study. The contact lengths, sizes of slip and stick regions, the normal and the shear stresses can be found.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.85.5-85
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• 2002

The Master-Slave manipulator is generally used as a remote handling device in the hot cell, in which the high level radio-active materials such as spent fuels are handled. This study describes a workspace mapping algorithm for a kinematically dissimilar master-slave system The algorithm provides the operator to guide the slave's end effector into unreachable regions which can appear due to the mismatch of workspace between the master and slave manipulator. A spaceball was used for the universal master device, and it can detect the slight fingertip force applied on the ball and also resolve the applied force. The spaceball device was also used to move 3D images instantaneously and simultaneou...