EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The discovery of Bulk Metallic Glasses (BMGs) has stimulated great interest not only from the scientific community but also from the industry. Thanks to the random atomic structures and concomitant lack of dislocations, BMGs exhibit excellent combinations of properties compared with their crystalline counterparts, such as extremely high strength and hardness, remarkable wear, and corrosion resistance [1]. So far, conventional processing technologies, e.g. die casting, injection molding, and thermoplastic forming, are unable to create BMG structures in complex geometries with more than a few centimeters of section-thickness [2].

Additive Manufacturing (AM) emerges as a promising technology to fabricate functional metal parts with customized geometries in near-net-shape. Among the AM technologies, selective laser melting (SLM) is, from a commercial point of view, one of the promising technologies to manufacture BMG parts beyond the limitations of classical fabrication methods. In spite of the fact that SLM process has inherent rapid cooling rates (reported values from ~10⁴ to~10⁶ K/s [2,3]), which are far above the critical cooling rates for most BMG-forming alloys, the production of high-quality, fully amorphous metals parts requires a careful adjustment of the processing parameters [4]. In particular, a fundamental understanding of the interplay between process parameters and crystallization processes is needed.

To this end, numerical and experimental investigations have been performed. The crystallization behavior is modeled based on our in-house developed software S$\mathbb{AM}$PLE^2D. The crystallization parameters determined from industrial-grade BMG are fed for the predictive simulation. The simulation is validated by experiments using different characterization methods, in terms of mechanical properties and microstructural evolution. In the end, the simulation results provide suggestions for further process parameter optimization.

References
[1] Kruzic, J.J., 2016. ADV ENG MATER.
[2] Jung, H.Y. et al., 2015. MATER DESIGN.
[3] Pauly, S. et al., 2018. ADDIT MANUF.
[4] Marattukalam, J.J. et al., 2020. ADDIT MANUF.