• Proceedings of the KWS Conference
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• 2003.05a
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• pp.90-92
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• 2003

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.2
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• pp.313-321
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• 2009

The construction of fiber-reinforced plastic (FRP) boats is decreasing trend since the application of international regulations on the control of marine environmental pollution, which recommended the use of environmentally friendly materials. The aluminum alloy used with material for ship is a superior to FRP. It is environmental friendly, easy to recycle, and provides a high added value to fishing boats. However, the welding for Al alloy materials have many problems, such as deformation by welding heat and effect of the working environment. In this paper, it was carried out welding by robot with welding material of ER5183 and ER5556 on 6061-T6 Al alloy for ship. The mechanical and electrochemical characteristics evaluated for specimen welded by robot. The cathodic polarization trend for the base metal and welding metal showed the effects of concentration polarization due to oxygen reduction and activation polarization due to hydrogen generation. The hardnesses of welding zone and heat affected zone are lower than that of base metal. At the result of tensile test, the specimen welded with ER5183 presented excellent property compared with ER5556.

• Korean Journal of Metals and Materials
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• v.46 no.7
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• pp.449-457
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• 2008

Compression deformation behaviors at high temperature as a function of temperature and strain rate were investigated in the 6061 aluminum alloy, which is used for automobile wheel. Compression tests were carried out in the range of temperatures $300{\sim}475^{\circ}C$ and strain rate $10^{-3}{\sim}10^{-1}sec^{-1}$. By analyzing these results, strain rate sensitivity, deformation temperature sensitivity, the efficiency of power dissipation, Ziegler's instability criterion, etc were calculated, which were plastic deformation instability parameters as suggested by Ziegler, Malas, etc. Furthermore, deformation processing map was drawn by introducing dynamic materials model (DMM) and Ziegler's Continuum Criteria. This processing map was evaluated by relating the deformation instability conditions and the real microstructures. As a result, the optimum forging condition for the automobile wheel with the 6061 aluminum alloy was designed at temperature $450^{\circ}C$, strain rate $1.0{\times}10^{-1}sec^{-1}$. It was also confirmed by DEFORM finite element analysis tool with simulation process.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.100-107
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• 2015

Recently, high-efficiency machining in the production of high-value products with a complex shape has constantly been required with the need for hybrid machining. In this study, in addition to the wire-cut E.D.M. and vibration used to present the possibility of a hybrid process by carrying out the aluminum alloy experiment, the hybrid process determines the nature of the surface. The selected experimental parameters are horizontality, waveform, amplitude, peak current, and frequency. The experimental results give guidelines for selecting reasonable machining parameters. The surface roughness was improved by about 20% with increases in the amplitude of the vibration.

• Journal of Welding and Joining
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• v.29 no.4
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• pp.73-79
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• 2011

Friction stir welding (FSW) is a solid state joining method patented in 1991 by The Welding Institute (TWI). It is widely used for joining light metals such as Al and Mg alloys. Foreign railway vehicle manufacturing companies have been applying FSW to car body welding, but domestic companies are in the beginning of feasibility study. Therefore, lots of experimental and analytical study is needed. In this study, three-dimensional finite element modeling of the friction stir welding of two Al6061-T6 plates was carried out. And temperature field and residual stresses were obtained and compared to experimental results in the literature. It is found the analytic thermal field is in a good agreement with the experimental results, but there are some differences between numerical and experimental residual stresses.

• Corrosion Science and Technology
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• v.21 no.6
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• pp.495-502
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• 2022

Anodization is a representative electrochemical surface treatment method that can improve both heat resistance and corrosion resistance by forming an anodization film on the surface of the aluminum. However, these properties can be changed after an additional heat treatment process. In this study, Al 6061 was subjected to an anodization process at 60 V for 1 hour, 5 hours, or 9 hours. An additional heat treatment process was performed at 500 ℃ for 30 minutes. Field emission scanning electron microscopy (FE-SEM) analysis revealed that the thickness of the anodized film was increased in proportion to the anodization time. Both pore size and pore diameter of the anodized film was also increased after anodization. After an additional heat treatment process, there were no significant changes in the thickness, pore size, or pore diameter of the anodized film. Heat resistance was confirmed through thermal analysis and chemical resistance was evaluated with a potentiodynamic polarization test.

• Composites Research
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• v.33 no.5
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• pp.241-246
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• 2020

In this study, aluminum (Al) alloy matrix composites in which B₄C particles were uniformly dispersed was manufactured through stir casting followed by hot rolling process. The microstructure, mechanical properties, and wear resistance properties of the prepared composites were analyzed. The composite in which the 40 ㎛ sized B₄C particles were uniformly dispersed increased the tensile strength and improved wear performance as the volume ratio of the reinforcement increased. In the case of the 20 vol.% composite, the tensile strength was 292 MPa, which was 155% higher than that of the Al6061. As a result of the wear resistance test, the wear width and depth of the 20 vol.% B₄C/Al6061 composites were 856 ㎛, and 36 ㎛, and the friction coefficient was 0.382, which were considerably superior to Al6061.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.907-908
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• 2010

• Proceedings of the KWS Conference
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• 1999.05a
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• pp.98-99
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• 1999

• Proceedings of the KWS Conference
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• 2001.10a
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• pp.202-205
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• 2001