Thermal and Microstructure Simulations for LPBF processes with Different Laser Beam Profiles

Abstract

Laser Powder Bed Fusion (LPBF) is a critical additive manufacturing technique for producing complex metal parts by selectively melting metal powder with a laser beam. The melt pool geometry directly in�fluences the quality, dimensional accuracy, and mechanical properties of the final component, making its control essential for optimal results. Traditionally, the Gaussian laser beam profile has been used in LPBF, but it often leads to localized overheating at the center of the melt pool, resulting in keyhole formation and other defects. To mitigate these issues, alternative laser beam profiles that combine Gaussian and ring-shaped profiles are explored. This combination helps to distribute the energy more evenly across the melt pool, reducing the risk of overheating and improving melt pool stability. In this study, different combi�nations of Gaussian and ring-shaped laser beam profiles are analyzed using an in-house developed finite volume (FV) code. The code simulates the thermal behavior of the melt pool in single-track LPBF and is validated against experimental data. Furthermore, a Cellular Automaton (CA) model based on the LGK dendrite growth theory is used to simulate microstructure evolution during solidification. The simulations provide insights into grain growth and the solidification microstructure, which directly influence the material’s mechanical properties. The thermal and microstructure simulations demonstrate the potential of different laser beam profiles to enhance the LPBF process. Additionally, the developed FV code and CA model offer valuable tools for advancing LPBF technology, enabling more precise control over laser beam shaping and melt pool behavior, ultimately improving part quality and reproducibility in future applications.