Ti alloys have many excellent properties, including low elastic modulus, desired corrosion resistance, nontoxicity, and biocompatibility. Hence, they promise to be major hard-tissue implant biomaterials (HTIBs). However, some properties, like surface hardness, wearability, and cellular activity, need to be enhanced. Moreover, their corrosion resistance in simulated body fluids and biocompatibility also need to be investigated systematically before practical applications. As HTIBs, the primary properties in clinical applications are wearability, corrosion resistance, and biocompatibility. Surface modification is a commonly used effective way to improve the above-mentioned disadvantages. This work is a brief review of the main surface modification technologies of Ti alloys for HTIBs (hereafter referred to as Ti alloys). The main surface modification technologies of Ti alloys are divided into four types, namely, physical technologies, chemical technologies, electrochemical technologies, and surface plastic deformation technologies. The principle and applications of these four types of surface modification technologies on Ti alloys are introduced one by one. Finally, the future directions for the surface modification of Ti alloys are proposed.

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The Ti‐30Zr‐5Al‐3V titanium alloy has an ultra‐low Young's modulus. So, it promises great application potential as a hard‐tissue implanted biomaterial. However, its surface performances need to be improved before clinical applications. In this work, a carbonated hydroxyapatite film is deposited on the surface of Ti‐30Zr‐5Al‐3V bio‐alloy using electrochemical methods. Microstructure, film‐substrate adhesion, and electrochemical corrosion behavior of carbonated hydroxyapatite deposited specimens in Ringer's solution are investigated. A homogeneous, dense, and fully covered carbonated hydroxyapatite film forms on the surface after depositing at 3 V, 90 °C for 120 minutes. The formation mechanism of the carbonated hydroxyapatite film on the micro‐nano structure surface is revealed. The corrosion performance of carbonated hydroxyapatite deposited specimens in Ringer's solution is evaluated by using potentiodynamic polarization curves. The carbonated hydroxyapatite deposition obviously enhanced the corrosion resistance of the Ti‐30Zr‐5Al‐3V bio‐alloy.