Nature Communications (Apr 2024)

Powder-size driven facile microstructure control in powder-fusion metal additive manufacturing processes

  • Shubham Chandra,
  • Chengcheng Wang,
  • Shu Beng Tor,
  • Upadrasta Ramamurty,
  • Xipeng Tan

DOI
https://doi.org/10.1038/s41467-024-47257-w
Journal volume & issue
Vol. 15, no. 1
pp. 1 – 14

Abstract

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Abstract Microstructure control in metal additive manufacturing is highly desirable for superior and bespoke mechanical performance. Engineering the columnar-to-equiaxed transition during rapid solidification in the additive manufacturing process is crucial for its technological advancement. Here, we report a powder-size driven melt pool engineering approach, demonstrating facile and large-scale control in the grain morphology by triggering a counterintuitive response of powder size to the additively manufactured 316 L stainless steel microstructure. We obtain coarse-grained (>100 μm) or near-monocrystalline microstructure using fine powders and near-equiaxed, fine-grained (<10 μm) microstructure using coarse powders. This approach shows resourceful adaptability to directed energy deposition and powder-bed fusion with no added cost, where the particle-size dependent powder-flow preheating effects and powder-bed thermophysical properties drive the microstructural variations. This work presents a pathway for leveraging feedstock particle size distribution towards more controllable, cost-effective, and sustainable metal additive manufacturing.