LPBF process of Zn-modified NiTi alloy with enhanced antibacterial response

Abstract. In this work the use of Laser Powder Bed Fusion (LPBF) process enabled the development of customized implants with advanced functional materials for the biomedical sector. In details, Ni rich NiTi Shape Memory Alloy (SMA) powder, mixed with Zn powder, were used for building samples, able to couple the typical superelasticity of the initial material with the antibacterial response, offered by the dopant element. The main parameters of the LPBF process were revised for achieving full dense parts. Further, the functional performances of the novel NiTiZn SMA were analyzed and compared with the ones of the reference material. Finally, the antibacterial response against different bacteria was tested. It was found a promising antibacterial response against Staphylococcus aureus of the NiTiZn SMA, while the addition of Zn into NiTi did not supress the martensitic transformation of the NiTi alloy and allowed to maintain the superelastic recovery.