Surface characteristics of nanotube-formed Ti-Ta-Ag-Pt alloys for dental implants / 대한치과재료학회지

ABSTRACT

In this study, the surface characteristics of nanotube-formed Ti-Ta-Ag-Pt alloys for dental implants were studied using various experimental instruments. The Ti-xTa-2Ag-2Pt quaternary alloys were manufactured using a vacuum arc-melting furnace with varying Ta contents (10, 30, and 50 wt%) and then homogenized by heat treatment at 1050 ℃ for 1 h. The nanotube formation of Ti-xTa-2Ag-2Pt (x = 10–50 wt%) alloy was performed using a DC power source of 30 V in 1.0 M H3PO4 + 0.8 wt% NaF electrolyte solution. The surface characterization was performed using optical microscopy (OM), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and wettability and nano-indentation tests. The microstructure of the Ti-xTa alloy was composed of an α''-phase (Widmanstätten structure) and a β-phase equiaxed structure. The XRD peak of the α phase became weaker and that of the β phase became stronger with increasing Ta content. The elastic modulus of Ti-30Ta-2Ag-2Pt alloy was lower than those of the other alloys. The highly ordered nanotubes were formed in the Ti-10Ta-2Ag-2Pt and Ti-30Ta-2Ag-2Pt alloys; nanoparticles were found in the Ti-50Ta-2Ag-2Pt alloy. The diameters of the large and small nanotubes increased and decreased, respectively, with increasing Ta content. Nanotubes did not grow in a needle-like structure (Widmanstätten), and nanotubes are not formed at the grain boundaries and edges. The anatase phase of TiO2 was detected in Ti-30Ta-2Ag-2Pt alloy and disappeared in Ti-50Ta-2Ag-2Pt alloy. The contact angle of the nanotube-formed Ti-30Ta-2Ag-2Pt alloy was lower than those of the other alloys.