Polyvinyl pyrrolidone (PVP) as an efficient and biocompatible binder for metal alloy processing: A case study with Ti-20Zr-11Nb-3Sn

Abstract

Titanium (Ti) being a lightweight, biocompatible, and strong metal, immense attention is being paid to develop Ti-based different low-cost and efficient biomedical implants by employing additive manufacturing (AM) or 3D printing. Binder having abundant binding efficacy binds the alloying metal powders and maintains their stoichiometry and close attachment. However, in the case of Ti-alloy, the Ti, or other alloying metals, e.g., zirconium (Zr), because of their high reactivity with ambient moisture and oxygen, needs to be stabilized before the alloy formation. In this work, instead of using various non-biocompatible thermoplastic and semi-crystalline polymers responsible for causing stress-induced defects in the final structure, the efficacy of a biocompatible amorphous polymer (i.e., polyvinyl pyrrolidone [PVP]) as a binder towards developing the Ti-alloy has been examined. PVP-bound alloying metal powders were found to be stable for 30 days (as per the XRD analysis) and exhibited a nearly similar composition to the experimental formula. Thermal debinding was examined for two temperatures, 600 and 1000 degrees C, and compared with the help of SEM and XRD analyses. The better debinding (i.e., reduction of carbon content as per the EDX analysis) was found for the 1000 degrees C debinding temperature.