Metal Additive Manufacturing Conference 2018

Laser-powder bed fusion (L-PBF) is an additive manufacturing process which is used in aerospace, automotive and medical applications. In these areas nickel, aluminum and titanium based alloys are already entrenched. For mechanical engineering industry only few steels are qualified for the L-PBF process which are mostly hot work tool steels with less than 0.5 wt.-% carbon content. Many applications need wear-resistant steel alloys with high hardness like high speed steels with higher carbon content. But processing these steels with L-PBF often leads to crack formation and is therefore considered as very challenging. This feasibility study demonstrates that building up dense and crack-free parts with a hardness over 60 HRC (as built) made from high speed steels (carbon content higher 0.5 wt.-%) with L-PBF is possible. Furthermore, the influence of typical L-PBF process parameters, especially preheating temperature, on the microstructure of the parts is evaluated.