Preparation of powders mixture of AISI S2 Tool Steel and Silicon Carbide for use in Laser Powder Bed Fusion

Mixing different powders is a promising way
to broaden the choice of materials for Laser
Powder Bed Fusion (LPBF). However,
powders for LPBF must present appropriate
rheological properties. Indeed, if the initial
batch of powders is not homogeneous, both
spreadability and laser - powder interaction
suffer, affecting the final part quality.
This work thus focuses on the preparation of
mixed AISI S2 tool steel and silicon carbide
(SiC) powders for use in LPBF. To promote
the complete dissolution of SiC in the melt
pool, spray dried granules of SiC
nanoparticles were selected. A combination
of sieving, ball milling and thermal treatment
was finally selected as it resulted in good
rheological properties of the powders mixture
and in a good quality of the final part.