Model of surface tension in the keyhole formation area during laser welding

Aleksander Siwek

AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Krakow, Poland.

DOI:

https://doi.org/10.7494/cmms.2013.1.0427

Abstract:

The nature of the laser welding process depends among others on the beam power density. Increasing the amount of energy supplied to the material, results in evolution from a shallow weld pool with flat surface, to the deep welding pool with a developed surface of the keyhole. The resulting gas/liquid surface boundary moves along with the laser beam and deforms, influenced by forces acting toward normal and tangential direction. Do not taking into account the curvature of the free surface, leads to non-physical values of the liquid velocity. In this study, for tracking and location of the interface, Volume of Fluid method (VOF) was used. It may be noted that the calculated contribution of the liquid phase, abruptly changes the value in the neighboring cells. In this paper we calculate the first and second derivatives of the liquid phase fraction function. Therefore, approximation of the normal vector and curvature of the free surface, requires the introduction of new, alternative smoothing rapid changes function. The value and direction of the force vectors were calculated, using the normal vector and curvature of the successive surface locations. The results were compared for different welding parameters.

Cite as:

Siwek, A. (2013). Model of surface tension in the keyhole formation area during laser welding. Computer Methods in Materials Science, 13(1), 166 – 172. https://doi.org/10.7494/cmms.2013.1.0427

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