Metals (May 2021)

Carbon Particle In-Situ Alloying of the Case-Hardening Steel 16MnCr5 in Laser Powder Bed Fusion

  • Matthias Schmitt,
  • Albin Gottwalt,
  • Jakob Winkler,
  • Thomas Tobie,
  • Georg Schlick,
  • Karsten Stahl,
  • Ulrich Tetzlaff,
  • Johannes Schilp,
  • Gunther Reinhart

DOI
https://doi.org/10.3390/met11060896
Journal volume & issue
Vol. 11, no. 6
p. 896

Abstract

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The carbon content of steel affects many of its essential properties, e.g., hardness and mechanical strength. In the powder bed fusion process of metals using a laser beam (PBF-LB/M), usually, pre-alloyed metal powder is solidified layer-by-layer using a laser beam to create parts. A reduction of the carbon content in steels is observed during this process. This study examines adding carbon particles to the metal powder and in situ alloying in the PBF-LB/M process as a countermeasure. Suitable carbon particles are selected and their effect on the particle size distribution and homogeneity of the mixtures is analysed. The workability in PBF-LB is then shown. This is followed by an evaluation of the resulting mechanical properties (hardness and mechanical strength) and microstructure in the as-built state and the state after heat treatment. Furthermore, potential use cases like multi-material or functionally graded parts are discussed.

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