Product Code: ICA13_402

Thermohydraulic Modeling of Pulsed Laser Welding
Authors:
Vincent Bruyere , CEA; Is sur Tille France
Charline Touvrey, Cea; Is Sur Tille France
Patrick Namy, cea; Grenoble France
Presented at ICALEO 2013

Nowadays, spot laser welding is a full fledged part of industrial manufacturing and is routinely used due to its advantage. It generates very located temperature gradients, and therefore, induces small distortions in the pieces.
Nonetheless, many welding tests are often performed in order to choose operating parameters leading to a narrow heat affected zones and defect-free joins.
This numerical study aims to increase our understanding of the link between operating parameters and the thermo-hydraulic evolution in the welding area, in the case of an isolated impact made with a Nd:YAG pulsed laser on a thin Ti6Al4V sheet. The COMSOL Multiphysics software is used to model both the interaction stage and the cooling one.
During the interaction, the free surface evolution is precisely described by a moving mesh method (ALE method). The dependence between the interface temperature and the recoil pressure is taken into account by an adaptation of the Clausius-Clapeyron law.
The keyhole collapse and the cooling stage are modeled by the Phase Field method (Eulerian method), which enables to consider the behavior of the gas trapped into the melting pool.
The numerical calculations have been compared to experimental characterizations (melted zone shape and defects position), in the case of relatively low laser power (inferior to 1000 W).