Effect of ball milling time on corrosion and wear resistance of Ti-13Nb-5Sn dental alloys

: Ti-13Nb-5Sn dental alloy was prepared by powder metallurgy method. The effects of ball milling time (3 , 12 , 24 h and 48 h ) on powder performances , material microstructure , electrochemical corrosion and tribological behavior were investigated. The results show that with the increase of ball milling time from 3 h to 48 h , the powder morphology gradually changes from bulky to fine particles , and a part of Nb and Sn atoms diffuse into Ti lattice to form a certain volume of Ti (Nb ) and Ti (NbSn ) solid solutions. Moreover , equiaxed alpha-Ti decreases and shifts into columnar grain boundary alpha-Ti , and the basket structure changes to Widmandelsteiner structure. The potentiodynamic polarization curves show that the corrosion potential (E corr ) and polarization resistance (R p ) of the alloy display an upward trend , the corrosion current density (I corr ) reveals a downward trend in artificial saliva (AS ) and simulated body fluid (SBF ). The corrosion resistance of the alloy is improved because of reduction of alpha-Ti and increase of beta-Ti. The hardness of the alloy increases , while the friction coefficient , wear depth and wear rate gradually decrease. More grain boundaries generate in sintering of the fine powder , resulting in the wear resistance of the alloy intensifying. The Ti-13Nb-5Sn alloy prepared by mechanical alloying combined with molding and sintering shows good corrosion and wear resistances , and has a great potential in the dental field.