• Proceedings of the KWS Conference
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• 2003.11a
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• pp.21-23
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• 2003

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

• Laser Solutions
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• v.6 no.1
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• pp.25-31
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• 2003

5052 aluminum alloy sheets of 2mm thickness were butt welded using a continuous wave Nd:YAG laser with and without Ar shielding gas. Vickers hardness, transverse-weld tensile and bulge tests were carried out to investigate the effect of Ar shielding gas on the mechanical properties and formability of laser welds. Porosity in the weld metals was investigated using an optical microscope. Mechanical properties and formability of 5052 aluminum alloy laser welds were degraded compared to those of base metal. However, those properties were improved due to the reduced size and number of porosity when Ar shielding gas was used.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.2
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• pp.91-95
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• 2005

A feasibility study was performed to see the welding possibility of dissimilar thin-plat materials. These materials were welded for finding the optimum welding condition and evaluating the soundness of welding zone. The welding was attempted under the condition of laser power 500~600w, Pulse width 1.0~2.5ms and frequency 11~18Hz. In this study, the highest tensile-shear strength was observed at laser the low frequency. The suitable welding condition can be obtain at the large pulse width and the low frequency.

• Journal of Welding and Joining
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• v.29 no.4
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• pp.80-84
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• 2011

In the 5xxx series Al-Mg alloy, magnesium addition can increase the strength of aluminum alloy by solid solution strengthening but it has a relatively low melting and boiling temperature. During full -penetration laser welding of the Al-Mg alloys, its low boiling point and high vapor pressure brings about the spiky humping bead on the bottom side. Under back-side shielding, the spiking of back bead can be reduced but it restraints the process flexibility. In this study, a square pulse waveform modulation was employed to stabilize keyhole and back bead surface without back-side shielding. By using an experimental design, the bead shapes were evaluated for various process parameters such as the focal position, welding velocity and waveform parameters and the smooth back bead shape could be achieved.

• Journal of Welding and Joining
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• v.22 no.2
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• pp.23-27
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• 2004

최근 레이저-아크 하이브리드용접에 대한 연구가 활발히 진행되고 있다. 이미 고출력 $CO_2$ 레이저가 보편화되면서 레이저용접이 차체제작에 널리 사용되고 있으며 고출력 Nd:YAG 레이저의 출현으로 알루미늄 레이저용접의 적용 가능성이 크게 증가하였을 뿐만 아니라 광화이버를 통하여 빔을 전달할 수 있어 좀 더 복잡하고 입체적인 물체를 용접할 수 있는 로봇 레이저 용접을 구현할 수 있게 되었다.(중략)

• Journal of Welding and Joining
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• v.31 no.1
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• pp.33-37
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• 2013

Robotized MIG welding of large aluminium components for high speed trains is state-of-the-art. The implementation of online laser cameras enables seam tracking and adoptive modification of welding parameters. A constant fill is achieved regardless of the gap tolerances. Friction Stir Welding has been introduced to the market as a reliable and fast joining technology. The advantages of high welding speeds and the elimination of arc light, fumes and liquefaction in the welding spot lead to economical realisation of heavy-duty gantry systems. FSW robots offer a high flexibility with regard to welding of curved parts, and can be equipped with laser cameras for exact joint tracking.

• Journal of Welding and Joining
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• v.23 no.5
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• pp.30-36
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• 2005

In this part, thermal finite element analysis(FEA) is conducted for the experiments in part 1. The molten area of base metals are analyzed by FEA results and compared with experimental ones. Temperature data from FEA results are used to calculate the IMC layer thickness analytically at the interface. IMC layer is established as a function of time and temperature when there is an interaction between solid steel and molten aluminum. The IMC layer thickness is obtained by cumulative computations using the time-temperature data from FEA results.

• Proceedings of the KWS Conference
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• 1999.05a
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• pp.274-277
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• 1999

• Proceedings of the KWS Conference
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• 1995.04a
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• pp.23-25
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• 1995