12 November 1986 Beam Absorption Mechanism In Laser Welding
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Mechanism of laser beam absorption was analyzed in key hole welding of thin plate and deep penetration welding of thick plate on the basis of the two-dimensional cavity model where beam is absorbed by cavity wall and ionized metal vapor. The beam absorptivity of the cavity wall A and the absorption coefficient of the plasma u are approximately 50 % and 1- 1.5 cm-1, respectively. In key hole welding of thin plate, laser beam is absorbed predominantly by the liquid cavity wall and the cavity shape is self-controlled so as to absorb the energy required for bead formation. In deep penetration welding of thick plate, laser power is absorbed mainly by plasma where the self-controlling is less effective, and hence excess energy absorbed at low welding speeds is w'sted to widen the bead with little increase in penetration depth. In vacuum of 10-3-10-4 torr, u decreases down to approximately 0.5 cm-1, providing large penetration depth.
© (1986) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Isamu Miyamoto, Isamu Miyamoto, Hiroshi Maruo, Hiroshi Maruo, Yoshiaki Arata, Yoshiaki Arata, } "Beam Absorption Mechanism In Laser Welding", Proc. SPIE 0668, Laser Processing: Fundamentals, Applications, and Systems Engineering, (12 November 1986); doi: 10.1117/12.938878; https://doi.org/10.1117/12.938878


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