Influence of Part Geometry and Feature Size on the Resulting Microstructure and Mechanical Properties of the Case Hardening Steel 16MnCr5 processed by Laser Powder Bed Fusion

Abstract

Additive manufacturing, especially laser powder bed fusion (LPBF), allows the build-up of complex parts. However, the resulting microstructure is not only influenced by the manufacturing parameters but also by the part geometry due to the influence on heat dissipation. At first, six geometric features are identified which can affect heat dissipation. Geometric samples of a case-hardening steel are produced via LPBF. Analysis of the microstructure and the mechanical properties show that the cross-sectional area and overhang angles have significant influence resulting in a hardness differences of more than 90 HV while increasing the ferrite content with increasing overhang angles. For further investigation, the results are analytically linked to the part density.