Effect of solid solution and aging treatment on the microstructure, mechanical properties, corrosion behavior and antimicrobial properties of Ti-5Mn alloys

Abstract

In this paper, Ti-5Mn alloy was subjected to different heat treatments to explore the possibility of preparing antimicrobial Ti-Mn alloys and to examine the effect of precipitate on the properties of the alloy. The microstructure, phase composition, hardness, biocorrosion properties and antimicrobial properties of Ti-5Mn alloys after different heat treatments was analyzed by metallurgical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), microhardness tests, electrochemical tests and antimicrobial tests. The results have shown that the phase composition of the solid solution treated Ti-5Mn(T4) was mainly β-Ti phase, and the aged Ti-5Mn was composed of α-Ti phase and Ti17Mn3 phase, while Ti17Mn3 precipitate gradually increased with the extension of the aging time. Ti-5Mn(T4) showed the highest hardness and the best corrosion resistance and the aging process reduced the hardness of Ti-5Mn(T4) alloy. With the precipitation of Ti17Mn3, the corrosion resistance of the alloy became worse and the hardness was reduced, but the corrosion resistance of Ti-5Mn alloy was still better than that of cp-Ti. It was demonstrated that Ti-5Mn(T4) exhibited no antibacterial properties against Staphylococcus aureus, but the aging treatment improved the antibacterial property of Ti-5Mn(T4) alloy, and the antibacterial rate of Ti-5Mn alloy reached 69% after 50 h aging treatment.