Effects of laser beam shaping on Ti-6Al-4V single tracks in PBF-LB/M: A study with Aconity MIDI+

The application of beam shaping is gaining increasing interest in laser-based additive manufacturing (AM) technologies, as it revolutionizes the process by providing additional control over incident energy distribution and the resultant microstructure and mechanical properties of the manufactured part. This study provides a comprehensive analysis of how different laser beam profiles (Mode 0, Mode 3, Mode 6), applied via the Aconity MIDI+ system, in combination with varied layer thicknesses (30 µm, 60 µm, and 90 µm) and linear energy inputs (up to 1.0 J/mm), influence single-track formation, surface morphology, roughness, and melt pool behavior in the Laser Powder Bed Fusion (PBF-LB/M) process of Ti-6Al-4V, offering new insights essential for process optimization. To further elucidate these effects, a complementary FEM model was used to analyze how beam shape affects melt pool dynamics and overall process stability. The findings reveal that transitioning from a conventional Gaussian beam (Mode 0) to a ring-shaped beam (Mode 3 and Mode 6) promotes conduction-mode melting, resulting in enhanced process stability and smoother melt track formation at higher linear energy densities. These beam profiles reduce certain defects, including spattering and balling, while producing wider and more stable melt tracks. Conversely, Mode 0 generates deeper melt pools, increasing the likelihood of keyholing and tracks surface roughness at elevated energy levels. While a thinner layer (∼30 µm) facilitates stable and smoother track formation across all beam profiles, thicker layers (≥60 µm) exacerbate surface roughness and defects, especially with Mode 0. In contrast, the ring-shaped beams produce wider, smoother, and more stable melt tracks at higher energy inputs (∼0.6–1.0 J/mm) with thicker layers. These insights are particularly valuable for high-performance applications in aerospace and biomedical industries, where precise control over surface quality and defect formation in Ti-6Al-4V components is essential for meeting certification standards and ensuring production efficiency. Overall, these findings highlight the critical role of beam shaping, layer thickness, and energy input in achieving stable melt tracks and improving the consistency and reliability of the PBF-LB/M process.

Subjects

Additive manufacturing

Beam shaping

Laser powder bed fusion

Ti-6Al-4V

DDC Class

621.3: Electrical Engineering, Electronic Engineering

660: Chemistry; Chemical Engineering

Funding(s)

RMIT European Doctoral Innovators Programme

Publication version

publishedVersion

Lizenz

https://creativecommons.org/licenses/by/4.0/

Name

1-s2.0-S0030399225013532-main.pdf

Type

Main Article

Size

23.29 MB

Format

Adobe PDF

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Effects of laser beam shaping on Ti-6Al-4V single tracks in PBF-LB/M: A study with Aconity MIDI+