Based on the well-known work of Arata et al. (IIW, Doc. IV, 1978) on the maximum temperatures generated at the workpiece surface by rectangular laser beams, we have derived the corresponding expressions for circular beams. The relations derived by Arata et al. for beams with a square cross-section were frequently used for the approximate determination of the deep-penetration threshold during laser welding (Beck, Modellierung des Lasertiefschweißens, Dissertation, B.G. Teubner, Stuttgart 1996). The expressions that we have derived now explicitly apply to Gaussian or top-hat beams with a circular cross-section as usually applied for welding and are in good agreement with experimental results.
For more details see T. Graf, P. Berger, R. Weber, H. Hügel, A. Heider, P. Stritt „Analytical Expressions for the Threshold of Deep-Penetration Welding“, Laser Physics Letters 12 (5), 056002 (2015).
Contact: Prof. Dr. Thomas Graf