TY - GEN
T1 - Application of electromagnetic force in laser welding
AU - Zhou, J.
AU - Tsai, H. L.
N1 - Publisher Copyright:
Copyright © 2007 by ASME.
PY - 2007
Y1 - 2007
N2 - In recent years, lasers have been widely used in the welding processes for automotive, aerospace, electrical and heavy manufacturing industries due to their high power density, small heat-affected zone and high productivity. Especially, with high depth-to-width ratio and high welding efficiency, keyholemode laser welding is more promising compared to the conventional welding processes. However, a number of defects, such as porosity, irregular beads, undercut and humping are frequently observed in laser welds, which deteriorates the strength and quality of the welded parts. In current study, an externally controllable electromagnetic force is introduced into the laser welding process to prevent porosity formation and to control weld bead shape. Numerical models are developed to study the transport phenomena in laser welding and to accurately calculate the current density and magnetic flux fields and the resulting electromagnetic forces in three-dimensional weldments. Effects of the electromagnetic force on metal flow, heat and mass transfer and weld bead shape are investigated. The continuum model is used to handle the entire domain including solid phase, liquid phase and mush zone. The enthalpy method is employed to handle the absorption and release of latent heat during melting and solidification. Inverse Bremsstrahlung (IB) absorption, Fresnel absorption and multiple reflections of laser beam energy at the keyhole walls are considered for the study of laser-plasma interaction. Volume of Fluid (VOF) technique is adopted to calculate the free surface evolution in the computation. As indicated by this study, porosity-free laser welds with desired bead shapes can be achieved with appropriate applications of electromagnetic forces.
AB - In recent years, lasers have been widely used in the welding processes for automotive, aerospace, electrical and heavy manufacturing industries due to their high power density, small heat-affected zone and high productivity. Especially, with high depth-to-width ratio and high welding efficiency, keyholemode laser welding is more promising compared to the conventional welding processes. However, a number of defects, such as porosity, irregular beads, undercut and humping are frequently observed in laser welds, which deteriorates the strength and quality of the welded parts. In current study, an externally controllable electromagnetic force is introduced into the laser welding process to prevent porosity formation and to control weld bead shape. Numerical models are developed to study the transport phenomena in laser welding and to accurately calculate the current density and magnetic flux fields and the resulting electromagnetic forces in three-dimensional weldments. Effects of the electromagnetic force on metal flow, heat and mass transfer and weld bead shape are investigated. The continuum model is used to handle the entire domain including solid phase, liquid phase and mush zone. The enthalpy method is employed to handle the absorption and release of latent heat during melting and solidification. Inverse Bremsstrahlung (IB) absorption, Fresnel absorption and multiple reflections of laser beam energy at the keyhole walls are considered for the study of laser-plasma interaction. Volume of Fluid (VOF) technique is adopted to calculate the free surface evolution in the computation. As indicated by this study, porosity-free laser welds with desired bead shapes can be achieved with appropriate applications of electromagnetic forces.
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U2 - 10.1115/IMECE2007-43479
DO - 10.1115/IMECE2007-43479
M3 - Conference contribution
AN - SCOPUS:84928614141
T3 - ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)
SP - 1025
EP - 1030
BT - Heat Transfer, Fluid Flows, and Thermal Systems
PB - American Society of Mechanical Engineers (ASME)
T2 - ASME 2007 International Mechanical Engineering Congress and Exposition, IMECE 2007
Y2 - 11 November 2007 through 15 November 2007
ER -