PSI - Issue 69

Mohammadjavad Abdollahzadeh et al. / Procedia Structural Integrity 69 (2025) 2–19

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Fig.13: temperature histories of the five marker points at laser power equal to 150 W and scan speed equal to 115 cm/s. In this figure the probes are considered vertically instead of horizontally. Because probe G is considered at a lowest level, so it has the lowest peak temperature.

4. Conclusion This study highlights the transformative potential of LPBF in fabricating high-performance components with complex geometries. Through an integrated approach combining CFD and CALPHAD, the research provides a comprehensive understanding of melt pool dynamics under realistic processing conditions. Key findings reveal the critical role of dynamic phenomena such as Marangoni convection, recoil pressure, and Rayleigh instability in shaping the melt pool morphology and mitigating defects. The temporal evolution of the melt pool further underscores the importance of thermal gradients and laser penetration depth in achieving consistent tracks. While the current work is centered on single-track formation, the insights gained—particularly regarding melt pool stability, heat distribution, and solidification behavior—can serve as a foundation for understanding more complex scenarios involving multi-track and multi-layer depositions. These extensions are crucial for industrial-scale applications, where track overlap, layer stacking, and thermal history become even more influential. Future work should incorporate these additional complexities to fully bridge the gap between controlled simulations and practical LPBF manufacturing. The formation of voids due to incomplete melting highlights the need to consider energy input relative to powder packing to ensure full melting. The transition of melt pool morphology from circular to comet-like, and the onset of instabilities such as Marangoni flow and Rayleigh instability, emphasize the importance of controlling temperature gradients and surface tension effects. Observed localized vaporization of Ni and Ti and temperature overshoot suggest that even at moderate powers, material evaporation and compositional changes are possible—thus, careful monitoring of peak temperature thresholds is crucial.