Mechanical properties of anodized TiNbSn alloy for biomedical applications

The mechanical properties of anodized TiNbSn alloy, prepared in an electrolyte of sodium tartrate acid with H₂O₂ under the application of a high voltage, were investigated in comparison with those of Ti6Al4V and pure Ti. The microstructure of anodized TiNbSn contains randomly distributed pores, whereas the anodic oxides on Ti6Al4V and Ti contain alternating layers with abundant and less abundant pores (mille-feuille structure). The hardness, surface roughness, and exfoliation strength of the anodized TiNbSn alloy were the highest among the samples investigated, and its Young's modulus remained unchanged after anodization. The wear resistance of the anodized TiNbSn alloy improved under both dry and wet friction conditions using Hank's balanced salt solution (HBSS). Anodized Ti generated debris on the abraded surface, and Ti6Al4V showed adhesive galling along with plastic deformation. However, no debris or galling appeared on the worn surface of the anodized TiNbSn alloy. The coefficient of friction of the anodized TiNbSn alloy under dry conditions decreased under wet conditions owing to the porous and rough surfaces allowing the penetration of liquid between the sample and abrasive SiC counterpart. We concluded that the anodized TiNbSn alloy exhibits excellent mechanical properties compared to Ti and Ti6Al4V alloy, and it could be utilized as an implant biomaterial.