Characterizing the influence of compositional and thermocapillary gradient variations on the temperature profiles and melt pool dimensions of LPBF-processed Al 7xxx alloys

Additive manufacturing (LPBF) is central to Industry 4.0, allowing the production of complex, high-precision parts across aerospace and manufacturing sectors. However, the observation, comprehension, or characterization of the melt pool dynamics and the complex transport phenomena within the melt pool during LPBF processes is challenging based on current experimental techniques. Accurately simulating these processes enables a comprehensive investigation of process windows and physical phenomena to obtain optimal process conditions, eliminating the need for costly and time-consuming experiments. Concerning the LPBF of Al 7xxx alloys, the thermal–fluidic transport effects on the temperature distribution and melt pool characteristics have been ignored. This study proposes an integrated experimental–computational framework to address these challenges. Building on our previous study of CALPHAD-based Al 7xxx alloy design, the designed alloys’ thermocapillary gradients were characterized using high-temperature (923–1513 K) sessile drop experiments and CALPHAD. Finally, finite element-based heat transfer–fluid flow models were developed using COMSOL Multiphysics software to simulate the LPBF process, utilizing the characterized thermocapillary gradient data. The results revealed that compositional and thermocapillary gradient variations affected the temperature distributions and melt pool dimensions. This model enhances the understanding of process–structure–property relationships in LPBF, aiding material design and process parameter optimization.