In situ alloying Ti–Ag antibacterial biomaterials via laser powder bed fusion: Microstructure, mechanical properties and bioperformance

Abstract

Antibacterial properties are critical for implants, while general pure titanium implants are bioinert. Adding nano Ag to metals is an effective strategy to obtain antibacterial properties. However, the comprehensive properties of Ti–Ag alloy prepared by traditional methods are not satisfactory. In this paper, Ti–5Ag alloy with an antibacterial rate close to 100 % was synthesized in situ by laser powder bed fusion (LPBF), and its microstructure and properties were studied systematically. Phase analysis demonstrated the existence of Ti₂Ag which played an important role in gaining excellent antibacterial properties. Benefiting from in situ laser alloying, the elements were homogeneously distributed, which endowed the Ti–5Ag alloy with excellent mechanical properties and corrosion resistance. The tensile strength and elongation reached 716 MPa and 33.51 %, respectively. Furthermore, through the design of triply periodic minimal surface (TPMS) structures, mechanical properties matching human bone were obtained. Based on LPBF-printed Ti–5Ag alloy and TPMS structures, this paper provides a feasible method for the manufacturing of bone implants with excellent comprehensive properties.