Authors:
Mohammadreza Jandaghi (1,2), Johan Moverare (1,2)
1-Division of Engineering Materials, Department of Management and Engineering (IEI), Linköping University, Sweden
2-Wallenberg Initiative Materials Science for Sustainability, Department of Management and Engineering (IEI), Linköping University, Sweden
Abstract:
The sustainability of Laser Powder Bed Fusion (L-PBF) in metallic component production hinges on effective powder reusing, given the significant unsolidified feedstock residue. This study evaluates the influence of powder reuse on phase evolutions using thermodynamic simulations via Thermo-Calc software. Both virgin and five-time reused powders of austenitic steel 316L (SS316L) were examined alongside printed parts. Results indicate unavoidable Rhodonite (MnSiO3) inclusions due to its high oxidation affinity. Rapid solidification produces ferritic single crystal particles from hot spatters. Sieving inefficiencies allow smaller oxide particles to persist, increasing oxide fractions in printed parts. Scheil diagrams show that while minor oxygen does not impact solidification, increased dissolved oxygen promotes Spinel (MnCr2O4) formation and inclusion clustering, serving as potential nucleation sites for ferrite. Tensile sample analysis reveals that, despite the pinning effect of fine oxide particles, increased inclusion size in reused samples compromises tensile strength.
DOI:
https://doi.org/10.59499/EP246281053
