Preliminary study of microstructure, mechanical properties and corrosion resistance of antibacterial Ti-15Zr-xCu alloy for dental application

摘要

Ti-15 Zr-xCu(3≤x≤7,wt.%) novel antibacterial and antibiofilm alloys with competitive mechanical properties,biological responses and corrosion resistance were designed and fabricated.Annealing heat treatment on Ti-15 Zr-7 Cu(TZC-7 A),after holding for 2 h at slightly above their beta transus temperature(BTT) ensured their tensile strength(UTS),yield strength(YS) and hardness(HRV) were improved by31.2%,20% and 12.3% respectively compared to the control without Cu,Ti-15 Zr(T-15 ZA).Although the3 wt.% Cu alloy displayed the highest elongation(26%),the TZC-7 A alloy also possessed a good ductility.Presence of evenly dispersed Ti2 Cu and Zr2 Cu Cu-rich intermetallic phases formed as interwoven and alternating lamellae within the α+β matrix as a result of Cu addition,as revealed by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).These greatly contributed to their strengthening and bactericidal properties.Over 98% antibacterial effect against E.coli and S.aureus have been imparted,coupled with excellent biofilm inhibition.Potentiodynamic polarization curves showed that the TZC-7 A alloy possessed higher corrosion resistance than commercially pure titanium,cp-Ti;contact angle test revealed enhanced hydrophilicity;while confocal laser scanning microscopy(CLSM) and cell counting kit(CCK-8) assays also displayed drastically lowered bacterial adhesion rate with comparatively no cytotoxicity.Cell attachment on all alloys was similar but the best spread was obtained on TZC-7 A after 24 h.The developed alloy has good potential as an antibacterial implant material with combination of optimized properties.