A volumetric heat source model for the approximation of the melting pool in laser beam welding

Abstract

Laser beam welding is a metal fusion technique that, with its high advance speed and low thermal distortion, is used more frequently nowadays in industry. During welding, the solidification front is located in the so‐called mushy zone, which forms the transition region between the completely solidified and mixture zone of solid and fluid material behind the laser beam. In this zone, various process parameters can lead to the formation of included melt areas that may cause cracking when they solidify and shrink. The properties of the solidification region are influenced by several parameters. Factors such as welding speed, temperature gradient, and chemical composition affect the likelihood of solidification cracking. To study the heat affected zone more accurately, different models describing the melting pool in finite element approaches using a heat source are discussed. The goal is to develop a volumetric heat source model based on the conical model, which closely represents the temperature distribution illustrated by the Lamé curves. Boundary value problems are presented to showcase the results.