In the field of metal surface treatment, passivation is a crucial technology, which is like putting an invisible armor on the metal to resist external erosion and extend its service life. For titanium alloys, this process is particularly crucial because titanium alloys shine in various fields such as aerospace, medical, chemical, etc. due to their lightweight, high strength, corrosion resistance, and other characteristics. The passivation treatment of titanium alloy is an important guarantee for its excellent performance. 1、 The secret of electrochemical passivation is the induction of a dense and stable oxide film on the surface of titanium alloy through the action of current. Among them, the anodizing method is particularly noteworthy. When titanium alloy is placed as an anode in an electrolyte and an appropriate voltage is applied, a nearly transparent oxide film gradually forms on its surface. This layer of film not only effectively isolates corrosive media, but also exhibits brilliant and colorful colors through the interference effect of light, from elegant silver gray to deep blue purple, each color is a perfect fusion of science and aesthetics. Details of anodizing method: Selection of electrolyte: A mixture containing phosphoric acid, sulfuric acid, and other components is usually used, which can promote the uniform growth of the oxide film. Voltage and time control: The voltage directly affects the thickness and color of the oxide film, while time determines the degree of oxidation reaction. Excessive voltage or prolonged time can cause the film layer to become too thick, and even lead to cracking of the film layer. Post treatment: After oxidation is completed, cleaning and sealing treatment should be carried out to ensure the integrity and stability of the oxide film. 2、 The art of heat treatment passivation is to use oxidation reactions at high temperatures to form a strong oxide layer on the surface of titanium alloys. This process is similar to the "Nirvana in Fire" in nature, where the surface of titanium alloy becomes more resilient through high-temperature baptism. The rapid cooling treatment is to ensure that the oxide layer can quickly solidify and form a dense structure, thereby improving its corrosion resistance. Key element: Temperature control: Temperature is the core parameter for heat treatment passivation. If it is too high, the oxide layer will be too thick and easy to peel off, while if it is too low, an effective oxide layer cannot be formed. Insulation time: The length of insulation time determines the thickness and uniformity of the oxide layer. Rapid cooling technology: The speed of rapid cooling directly affects the structure and performance of the oxide layer. 3、 The fine process of chemical treatment passivation includes two steps: acid washing and chemical passivation. Acid washing can remove oil stains, oxides, and other impurities on the surface of titanium alloys, creating a clean substrate for subsequent chemical passivation. Chemical passivation, on the other hand, involves the reaction of specific chemical substances with the surface of titanium alloys to form a dense oxide film. The detailed operation of acid pickling and passivation: pre-treatment: mechanical cleaning and degreasing are essential pre steps, which can ensure the cleanliness of the titanium alloy surface. Selection and ratio of pickling solution: Nitric acid solution has become the mainstream choice in this field due to its strong oxidizing properties and good compatibility with titanium alloys. However, attention should be paid to the accuracy of the ratio to prevent the production of harmful "yellow smoke". Time control: The pickling time needs to be accurately controlled. If it is too long, it will introduce too much hydrogen element, which will affect the performance of titanium alloy; If it is too short, the ideal cleaning effect cannot be achieved. Post treatment: Water washing and drying are key steps to ensure the effectiveness of acid washing. Water washing needs to thoroughly remove residual acid, while drying needs to avoid leaving water stains on the surface. Passivation treatment of titanium alloy is a technology that combines scientific and artistic aspects. Through various methods such as electrochemistry, heat treatment, and chemical treatment, we can construct a strong and beautiful oxide film layer on the surface of titanium alloys, significantly improving their corrosion resistance and surface quality. In the future development, with the advancement of technology and innovation of processes, the passivation treatment technology of titanium alloys will surely usher in a broader application prospect.