With the growing demand for titanium building materials, higher requirements have been put forward for the use of titanium alloys. Titanium alloy has been widely used in aerospace, automobile manufacturing, building decoration and other fields due to its light weight, high strength, excellent corrosion resistance and other characteristics. In order to meet the demand for titanium alloy performance in different fields, the surface treatment technology of titanium alloy is particularly important.
I. Overview of surface treatment technology of titanium alloy
1. Sandblasting treatment: the use of white corundum rough spray treatment of titanium castings surface, can remove sticky sand, sintered layer and part of the oxide layer. This process is usually controlled at a pressure of 0.45Mpa or less and a time range of 15~30 seconds.
2. Chemical pickling: Using HF-HCl and HF-HNO3 pickling solution, the reaction layer on the surface of titanium alloy can be removed quickly and completely, and the contamination of other elements can be reduced at the same time. HF-HNO3 pickling solution can reduce the amount of hydrogen absorption by controlling the concentration of HNO3, and realize the bright treatment.
3. AC micro-arc oxidation: instantaneous high-temperature and high-pressure sintering in the micro-arc discharge zone directly turns the base metal into oxide ceramics, forming a thicker oxide film and improving the anti-wear and anti-corrosion properties of titanium alloy.
4. Ion injection: such as nitrogen ion injection, can improve the tribological properties and hardness of titanium alloy, while maintaining the geometric accuracy of the workpiece.
5. plasma nitriding and shot peening: nitriding layer composed of TiN, Ti2N and other phases is formed on the surface of titanium alloy, and the shot peening deformation strengthening post-treatment improves the wear resistance and resistance. 6. laser cladding: excellent coating is obtained on the surface of titanium alloy to improve its high-temperature wear and corrosion resistance, which is commonly used in the repair of gas turbine engine parts.
7. anodizing: anodizing under specific conditions, such as after crystallization of large ice flowers, to beautify the appearance and improve corrosion resistance.
8. drawing treatment: drawing silk-like patterns on the surface of titanium alloy to increase the texture, commonly used in consumer electronics products and other fields.
9. Mirror polishing: make the surface of titanium alloy as smooth as a mirror, with high reflectivity, applicable to the need for aesthetic and high reflective properties of the occasion.
In addition, there are molten salt treatment and other pretreatment methods can assist the above methods to obtain better results. In practice, according to the specific application and requirements of titanium alloy, we can choose or combine various treatment methods to achieve the best effect.
Second, the special needs of titanium alloy surface treatment
In addition to the conventional mechanical properties, the surface treatment of titanium alloy also needs to consider some special needs.
1. Anti-discoloration treatment: titanium is easy to oxidize and discolor in contact with oxygen, and glass and other coverings can be used to prevent or delay discoloration. Oxidation coloring and corrosion treatment can obtain unique artistic effects, such as colorful sculptures.
2. Anti-brilliant treatment: low surface gloss and soft color are required. Non-glossy fine rolling, pickling, shot blasting treatment and other methods can be used to make the surface of titanium plate in a micro-convex shape, reducing the gloss.
In summary, the surface treatment technology of titanium alloy is diverse, and suitable methods can be selected according to different needs. With the progress of science and technology and the growth of demand, the surface treatment technology of titanium alloy will continue to develop, providing stronger support for the application of titanium alloy.
