A high strength,wear and corrosion-resistant,antibacterial and biocompatible Nb-5 at.％ Ag alloy for dental and orthopedic implants

Refractory metal niobium (Nb) incorporated with a small amount of silver (Ag),the resulting Nb-Ag two-phase alloys,were fabricated by mechanical alloying and spark plasma sintering.The microstructure,mechanical properties,wear resistance,corrosion behavior,in vitro and in vivo antibacterial properties and biocompatibility of the Nb-Ag alloys were systematically investigated.The results show that the mechanical properties,wear resistance,corrosion resistance and antibacterial ability were significantly enhanced after addition of 5 at.％ Ag.The fabricated Nb-5 at.％ Ag alloy demonstrates high yield strength of up to ～ 1486 MPa and fracture strain of ～ 35 ％.The precipitated Ag particles could reduce friction and wear.The enhanced corrosion resistance was attributed to the higher relative density of the sintered alloys and the formation of a stable and dense passive film of niobium and silver oxides.In vitro and in vivo evaluations show that the Nb-5 at.％ Ag alloy also has strong antibacterial activity and good biocompati-bility and osteointegration ability.These results demonstrate great potential of the nanostructured Nb-Ag alloys for dental and orthopedic implants.