Scientific Reports (Dec 2023)

In-situ directed energy deposition of Al based low density steel for automotive applications

  • Matěj Rott,
  • Ying Li,
  • Martina Koukolíková,
  • Martina Šípová,
  • Pavel Salvetr,
  • Zbyšek Nový,
  • Gerhard Wolf,
  • Jan Džugan

DOI
https://doi.org/10.1038/s41598-023-49026-z
Journal volume & issue
Vol. 13, no. 1
pp. 1 – 9

Abstract

Read online

Abstract This work deals with the fabrication of one low density steel by mixing AISI S2 tool steel and AlSi10Mg powders using powder-based directed energy deposition (P-DED) technique. Two approaches of mixing powders were compared-continuous mixing during the process (in-situ) and mixing the powder prior to the process (premixed). The P-DED sample was characterised by a variety of techniques such as optical microscopy, scanning electron microscopy, electron backscatter diffraction, X-ray diffraction, and hardness measurement. Our findings demonstrate the successful achievement of steel with a 8 wt. % AlSi10Mg addition when two dissimilar powders are premixed, resulting in approximately 12% reduction in the density of S2 steel. Optimizing the powder feed rate and the ratio of AlSi10Mg powder contribute to an improvement of printability, eliminating materials separation, leading to a homogenous deposited part. Compared to the in-situ mixing case, the premixed process within the current process window generates a more homogeneous microstructure consisting of three phases: Ferrite, Fe3Al and Fe3AlC carbide. Whereas, the in-situ sample exhibits only two phases Ferrite and Fe3Al. The hardness of the premixed sample is found to be slightly higher compared to the in-situ sample.