The colored surface of titanium is due to surface oxidation to generate titanium dioxide. Different thicknesses of the titanium dioxide oxide film refract light in different colors, so many different colors are formed. Generally, the coloring and oxidation of titanium is divided into atmospheric method, anodizing method and deposition method. Today we will introduce the most commonly used anodizing method.
Titanium anodizing, titanium and its alloys are placed in corresponding electrolytes (such as sulfuric acid, chromic acid, oxalic acid, etc.) as anodes, and electrolysis is performed under specific conditions and applied current. The titanium or its alloy on the anode is oxidized, and a thin layer of titanium oxide is formed on the surface. Its thickness is 5 to 30 microns, and the hard anodic oxide film can reach 25 to 150 microns. Anodized titanium or its alloys have improved hardness and wear resistance, up to 250-500 kg/mm2, good heat resistance, hard anodized film melting point as high as 2320K, excellent insulation, impact resistance The breakdown voltage is as high as 2000V, which enhances the corrosion resistance and does not corrode after thousands of hours in ω=0.03NaCl salt spray. The thin layer of the oxide film has a large number of micropores, which can absorb various lubricants and is suitable for manufacturing engine cylinders or other wear-resistant parts; the film has strong adsorption capacity and can be colored into various beautiful and bright colors. Non-ferrous metals or their alloys (such as titanium, magnesium and their alloys, etc.) can be anodized. This method is widely used in mechanical parts, aircraft and automobile parts, precision instruments and radio equipment, daily necessities and architectural decoration, etc. Generally speaking, titanium or titanium alloy is used as the anode, and a lead plate is used as the cathode. The titanium and the lead plate are placed together in an aqueous solution, which contains sulfuric acid, oxalic acid, chromic acid, etc., for electrolysis, and the titanium and lead plates are An oxide film forms on the surface.
The surface of pure titanium products has a dense oxide film, which can adapt well to various environments at room temperature. Therefore, no spraying is required, and pure titanium kettles have strong corrosion resistance. In the face of outdoor weak acid or weak alkali environment, pure titanium kettle can cope with it easily. Whether it is river water, rainwater, rocks or vegetation, pure titanium kettle can be in direct contact with it without being corroded. Since the entire body of the kettle is not painted, the kettle presents a unique gray color that is unique to pure titanium products, and can also be heated directly on a fire source to produce colorful colors. The colorful color of titanium kettles. The surface of titanium metal is covered with an extremely thin layer of naturally occurring oxide film (titanium and oxide TiO2). This film can also become titanium rust, because a transparent film with a high refractive index is formed on the surface. The film acts as a prism, refracting light and absorbing light of different wavelengths, and then you can see the color. Moreover, if this is If the thickness of the oxide film is manually adjusted to 8~10um, thousands of similar colors can be displayed depending on the wavelength. Because this film is a transparent film with a high refractive index, it can display rich colors.
