New Partially Water-Soluble Feedstocks for Additive Manufacturing of Ti6Al4V Parts by Material Extrusion

In this work, a process chain for the realization of dense Ti6Al4V parts via different material
extrusion methods will be introduced applying eco-friendly partially water-soluble binder systems.
In continuation of earlier research, polyethylene glycol (PEG) as a low molecular weight binder
component was combined either with poly(vinylbutyral) (PVB) or with poly(methylmethacrylat)
(PMMA) as a high molecular weight polymer and investigated with respect to their usability in FFF
and FFD. The additional investigation of different surfactants’ impact on the rheological behaviour
applying shear and oscillation rheology allowed for a final solid Ti6Al4V content of 60 vol%, which is
sufficient to achieve after printing, debinding and thermal densification parts with densities better
than 99% of the theoretical value. The requirements for usage in medical applications according to
ASTM F2885-17 can be fulfilled depending on the processing conditions.