Morphology and texture characterization of grains in laser welding of aluminum alloys

Grain morphology and texture of welds significantly affect the properties of the corresponding joint. It is very important to determine how heat and grain growth during welding correlate. Our studies involved both experiments and multi-scale numerical modeling. The laser welding temperature distribution was studied by the macroscopic finite element method. The grain growth and morphology evolution under different heat input conditions were calculated by the Monte Carlo method at the mesoscale. The relationship between heat flow distribution and grain orientation was established. Results of electron backscattered diffraction (EBSD) were compared to those obtained by numerical modeling. The welding heat input affected the heat flow distribution and the shape of the molten pool, which, in turn, influenced grain morphology and crystal orientation.