• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.388-389
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• 2019

초박판 용접 기술인 CMT (Cold Metal Transfer) 용접을 위한 모터의 고정밀 정역동작 알고리즘 연구개발 결과를 본 논문에서 발표한다. CMT 용접 기술 구현을 위해 50W급 고정밀 속도 및 토크 제어가 가능한 맥슨모터의 EC-i40(BLDC 모터)을 사용하였고, DSP(TMS320F28069)와 모터 드라이버 IC(A3930)를 적용한 전용 제어 보드를 제작하여 CMT 동작 성능을 검증하였다. 실제 상용화되고 있는 용접전원장치(HF400R)와 본 논문에서 발표하는 CMT 기술을 연동하여 용접을 수행하면서 그 우수성을 확인하였다.

• 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 Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.21-30
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• 2017

Of the marine engine components, the piston crown and exhaust valve are repaired most frequently. These works are conducted through conventional welding processes such as GTAW or SAW, domestically in marine engine repair factories. New high-efficiency welding or overlay processes such as tandem SAW, tandem MAG, hybrid TIG-MIG welding, pulsed-GMAW, CMT welding, and super TIG welding have been developed recently. Moreover, the plasma transfered arc (PTA) process is an efficient spray method for overlaying on the exhaust valve. In this review paper, the new high-efficiency repair welding methods are introduced for marine engine components. The problems due to repair welding for marine engine components are also presented.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.50-50
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• 2009

본 연구에서는 차체 부품의 경량소재 대체에 따른 Panel Assembly Rear Seat Back 부품 제작에 최신 저입열 미그용접공정을 적용한 TWB(Tailor Welded Blank) 공정기술을 확보하기 위해 최적 용접조건 도출에 관한 연구를 진행하였다. 용접 후 성형이 이뤄지는 제조공정의 특성 상 성형강도에 중점을 둔 실험을 진행하였으며, 이를 위해 각 와이어에 따른 용접부의 기계/금속학적 특성이 평가되었다. 대상 시편은 6천계열 열처리형 합금이며, 두께는 각각 1.6t, 1.4t로 이를 맞대기 용접 후 그 특성을 평가하였다. 용접은 저입열 GMA용접 공법 중 하나인 CMT 용접법(Cold Metal Transfer)을 사용하였으며, 평가 대상 와이어로는 4043, 4047, 5183 및 5356이 사용되었다. 특성평가는 마크로 및 마이크로 조직, 경도, 인장강도, 기공 및 결함, 성형강도 등에 대해 이뤄졌으며, 희석된 와이어의 조성이 용접부 특성에 미치는 영향에 대해서도 검토되었다. 실험 결과, 5천계열 와이어가 성형강도에 비교적 더 강인한 결과를 나타냈으며 성형강도는 용접조건 및 초기 갭에 대한 영향은 받았으나, 비드형상과 강도간의 연관성은 찾을 수 없었다. 이에 따라 TWB 적용을 위한 와이어로는 5356이 가장 우수한 것으로 판명되었다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.110-115
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• 2016

The need for high-strength galvanized steel has recently increased because of the increased number of car consumers who want improved efficiency and exterior quality. High-strength galvanized steel with high corrosion resistance improves the durability of products and exterior quality. Furthermore, the gilt of zinc does not come off during machining because of the fine adhesive property of zinc. When these are welded, zinc has a lower melting temperature than iron, so zinc is more quickly vaporized than iron. Vaporized zinc can stick to electrodes, which increases spatter in welding transportation. Created spatter can enter the molten pool and develop into inner defects or blowholes and pits. Scattered spatter sticks to the product, which leads to the secondary cost of spatter removal. Therefore, in this study, comparisons of amounts of spatter generated are conducted according to the composition of shielding gas in the MIG and CMT processes to find optimal welding parameters.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.369-370
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• 2012

• Proceedings of the KWS Conference
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• 2008.05a
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• pp.41-41
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• 2008

• Journal of Welding and Joining
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• v.31 no.1
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• pp.26-32
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• 2013

Recently, welding technology of nonferrous metals which were difficult to implement by arc welder has become available through digitalization of arc welding machine. Among them, the welding quality improvement of aluminum welding is very noticeable. These results increase the arc stability by controlling arc current and voltage waveform precisely, and control wire feed speed by synchronizing with arc current which the feed rate of filler wire is controlled by a precise motor control of servomotor and not by a simple constant speed feeding. Not only through the hardware digitalization of arc welding machine but also through advance of software of arc welding, it became possible to implement a certain level of welding quality by a simple operation. These led to CMT welding process implementation which requires low heat input than current arc welding and highly increased the applicability of the aluminum welding.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.2
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• pp.288-294
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• 2009

The purpose of this study is manufacturing of monolithic housing for modularization of steering gear. Monolithic housing is difficult to weld with only rotation and linear motion. It is for this reason that housing of joining parts have a slope of 76.3 degrees. For this reason, welding trajectory was measured by the cooperative controled robot system, and then allowing for measured results, we developed the dedicated system. The developed system can be welded by using only 3 axises in contrast with robot system using 8 axises in housing welding. In addition, we applied CMT and laser welding device to dedicated system and as a result of experiment, sound bead and excellent roundness could be obtained.

• Proceedings of the KWS Conference
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• 2005.11a
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• pp.147-149
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• 2005

최신 연구 결과에 따르면 알루미늄과 스틸의 접합으로 산업용 부품의 특성을 향상시킬 수 있음을 알 수 있다. 특히, 자동차 산업에서는 알루미늄과 스틸의 접합이 가능해짐으로써 에너지 소모량을 최소화할 수 있다. 지금까지 이 두 소재는 대부분 클린칭이나 스크류잉과 같은 기계적인 방법으로 접합을 하였다. 열에 의한 접합은 금속간 상(Intermetallic Phase, IMP)이 형성되기 때문에 극히 제한되었다. 이러한 상은 취성이 높기 때문에 접합부의 물성을 악화시킨다. 그 밖에도 알루미늄과 스틸의 접합에 레이저 시스템과 프레스 장치를 결합하여 사용하는 방법도 있다. 본 연구논문에서는 아연도금강과 6공 계열 알루미늄 합금(AIMgSi)이나 제한적이긴 하지만 5공 계열 알루미늄 합금(AIMg)을 접합하는데 일반 GMAW 프로세스를 변용하여 방법에 대하여 논하고자 한다.