## 1 Introduction  
Titanium and its alloys have been considered as some of the most suitable implants for the replacement and repair of human hard tissues because of their good corrosion resistance, mechanical properties and biocompatibility [1; 2; 3; 4]. Among the various titanium alloys, Ti-6 Al-4V and Ti-6 Al-7 Nb have been widely used owing to their good properties [3; 5; 6]. However, they are easy to dissolve and can undergo aseptic loosening in physiological environments due to the complex electrolyte environment in human bodily fluids, as well as the comprehensive action of active cells [2; 5]. Furthermore, some studies have revealed that the corrosion and wear behavior of Ti-6 Al-4V leads to the diffusion of aluminum and vanadium into the blood, causing local inflammation, allergies, poisoning, and diseases such as Alzheimer's disease [6; 7]. In addition, the two-phase (\(\alpha\)+\(\beta\)) Ti-6 Al-4V has poorer corrosion resistance than the single-phase due to the galvanic coupling effect [8]. Therefore, there has been a continuing interest in exploring new materials with excellent properties and no toxicity. Surface modification treatment on existing materials is a feasible solution.  
Ion implantation is a surface modification technique, in which high-energy ion beams are implanted onto the surface of a material and eventually remain inside to optimize the surface performance [9]. At present, ion implantation has been widely used in the surface modification of Ti and its alloys in the medical field [10; 11; 12; 13; 14]. [PERSON] et al. [13] implanted Zr ions into a titanium surface and revealed that a Ti-Zr alloy layer on titanium exhibited good mechanical properties and corrosion resistance. [PERSON] et al. [15] observed that the generation of Nb\({}_{2}\)O\({}_{5}\)/TiO\({}_{2}\) and implanting Nb ions into a Ni-Ti alloy significantly improved the corrosion resistance of the composite film in [PERSON]'s solution. [PERSON] et al. [16] implanted Nb ions to obtain a wear-resistant modified layer in Ti-Al-Zr, and the wear-resistance improved because of the formation of intermetallic NbTi\({}_{4}\). Studies have shown that the presence of Nb can stabilize the passivated film of Ti alloys, improve the corrosion resistance, and improve its wear-resistance [15; 17].  
Titanium alloys are prone to corrosion and wear phenomena coming from the hostile environment of the body and friction processes, and sometimes the wear and corrosion behaviors of titanium alloys occur simultaneously when used as an implant material. Therefore, it is necessary to study the tribocorrosion problem in bodily fluids while studying corrosion behavior, as it is more meaningful for practical application and provides data references for practical application.  
In this paper, Nb ions were implanted into the single-phase TA3 with a dose of \(6.85\times 10^{16}\) ions/cm\({}^{2}\) at an energy of 125 keV. The surface morphology, phase structure, mechanical properties, corrosion and tribocorrosion behavior of the samples in [PERSON]'s solution were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), friction and wear instrument and nanoindentation instrument, combined with electrochemical measurements.