Preparation method for dopant-free low-defect colored anode oxide film on surface of titanium

The invention discloses a preparation method for a dopant-free low-defect colored anode oxide film on the surface of titanium. The surfaces of titanium and titanium alloy products is subjected to rackclamping after being pretreated, anodic oxidation treatment is conducted under a certain solution system through a direct current power source, the anode voltage is 10-110 V, the oxidation time is 30-120 s, and the dopant-free low-defect colored anode oxide film is obtained. The direct current power source has a constant voltage output function, a voltage feedback compensation function and a post-compensation voltage boosting control function, the voltage boosting rate at the moment that anodic oxidation is started can be controlled, the voltage is reduced to the appropriate voltage range, and the stability and consistency of colors are improved. The anode oxide film obtained through the method is not doped with other elements except the base element, and is good in biocompatibility and high in color fastness. 本发