CFD modeling for predicting imperfections in laser welding and additive manufacturing of aluminum alloys

Aluminum and its alloys are widely used in various applications including e-mobility applications due to their lightweight nature, high corrosion resistance, good electrical conductivity, and excellent processability such as extrusion and forming. However, aluminum and its alloys are difficult to process with a laser beam due to their high thermal conductivity and reflectivity. In this article, the two most used laser processes, i.e., laser welding and laser powder bed fusion (LPBF) additive manufacturing, for processing of aluminum have been studied. There are many common laser-material interaction mechanisms and challenges between the two processes. Deep keyhole mode is a preferred method for welding due to improved productivity, while a heat conduction mode is preferred in LPBF aiming for zero-defect parts. In LPBF, the processing maps are highly desirable to be constructed, which shows the transition zone. Presented numerical modeling provides a more in-depth understanding of porosity formation, and different laser beam movement paths have been tested including circular oscillation paths. High accuracy processing maps can be constructed for LPBF that allows us to minimize tedious and time-consuming experiments. As a result, a modeling framework is a highly viable option for the cost-efficient optimization of process parameters.