• 제목/요약/키워드: $CO_2$ Laser Welding

검색결과 201건 처리시간 0.035초

레이저 빔의 흡수 액체 내 침투에 의해 생성된 키홀 구조와 안정성 (Keyhole-structure and Stability in Laser-beam Penetration Into an Absorbing Liquid (Water))

  • 김동식;장덕석
    • 한국레이저가공학회지
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    • 제4권2호
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    • pp.13-19
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    • 2001

  • When a high-power laser beam is irradiated on the surface of material, it is well known that a cavity, called a keyhole induced by the pressure action of the vapor plume, is generated in the molten material. This paper describes the interaction between a pulsed CO$_2$ laser beam and water. The laser-beam is used to generate and maintain a conical depression in the water surface similar to the keyhole created during laser penetration welding. Experimental results show that the depth of laser-beam penetration is limited by hydrodynamic instability. The instability of the surface cavity can be understood by the capillary instability of a hollow jet. Theoretical computation of the steady keyhole shape has been performed. modifying the model suggested by Andrews et al. (1976). The model predicts the qualitative behavior of the keyhole but significantly underestimates the average diameter.

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OPTIMAL PROCESSING AND SYSTEM MANUFACTURING OF A LASER WELDED TUBE FOR AN AUTOMOBILE BUMPER BEAM

  • Suh, J.;Lee, J.H.;Kang, H.S.;Park, K.T.;Kim, J.S.;Lee, M.Y.;Jung, B.H.
    • International Journal of Automotive Technology
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    • 제7권2호
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    • pp.209-216
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    • 2006

  • A study has been conducted for an optimal processing and an apparatus for manufacturing a laser welded tube for one-body formed bumper beam. The tube dimensions used in calculation were the thickness of 1.4 mm, the diameter of 105.4 mm and the length of 2000 mm. The tube was formed of a cold rolled high strength steel plate(tensile strength of 600 MPa). The two-roll bending method was the optimal tube forming process in comparison with the UO-bending method, the bending method on the press brake, the multi-step continuous roll-forming method and the 3-roll bending method. Monitoring of the welding quality was conducted and the seam tracking along the butt-joint lengthwise to the tube axis was also examined. The longitudinal butt-joint was welded by using a $CO_2$ laser welding machine equipped with a seam tracker and a plasma sensor. The $CO_2$ laser tube welding machine could be used for precise seam tracking and real-time monitoring of the welding quality. As a result, the developed laser welded tube could be used for a one-body formed automobile bumper beam.

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