Analysis of surface modification technology of titanium alloy rods and pure titanium rods

Surface modification technology of titanium alloy rods and pure titanium rods is researched to improve their performance, corrosion resistance and mechanical properties. These modification techniques usually involve surface treatment, coating, oxidation, sandblasting and other methods. The following are some common surface modification technologies for titanium alloy rods and pure titanium rods:
The surface modifications of pure titanium rods and titanium alloy rods mainly include: anodizing, nitriding, atmospheric oxidation, ion implantation, chemical surface modification, etc.
●Anodizing: including thermal oxidation and anodizing. The anodizing technique for titanium rods is relatively easy. In some oxidizing media, under the action of external voltage, titanium anode can form a thicker oxide film, thus improving its corrosion resistance, wear resistance, and weather resistance. The electrolyte for anodizing generally uses H2SO4 and acidic aqueous solution.
●Nitriding: Chemical heat treatment technologies such as plasma nitriding, multi-arc ion plating, ion implantation, and laser nitriding are used to form a golden TIN coating on the surface of titanium dentures, thereby improving the wear resistance and corrosion resistance of titanium. and fatigue resistance, but the surface modification technology of titanium dentures is complex and the equipment is expensive, making it difficult to achieve clinical practicality.
●Atmospheric oxidation: Titanium rods can form a thick and strong anhydrous oxide film in a high-temperature atmosphere, which is effective against both overall corrosion and crevice corrosion of titanium. The method is relatively simple.
●Surface sandblasting: Sandblasting can change the roughness of the titanium surface and increase its surface energy, thereby improving wettability and adhesion.
●Electrochemical polishing: Electrochemical polishing can make the titanium surface smoother, improve its surface quality, reduce surface defects, and help improve corrosion resistance.
●Coating technology: Applying different types of coatings, such as ceramic coatings, hard coatings, etc., can improve the hardness and wear resistance of titanium surfaces.
●Ion implantation: Changing the chemical composition of the titanium surface through ion implantation can improve its hardness, wear resistance and corrosion resistance.
●Plasma spraying: Through plasma spraying technology, a ceramic coating can be formed on the surface of titanium to improve its surface hardness and wear resistance.
●Laser treatment: Laser can be used to locally heat and change the structure of the titanium surface, improving its surface hardness and wear resistance.
●Chemical surface modification: Use chemical methods to change the chemical composition of the titanium surface to form a specific compound layer to improve its performance.
Pure titanium rods and titanium alloy rods can easily react with O, H, N and other elements in the air and Si, AL, Mg and other elements in the investment mold at high temperatures, forming a surface pollution layer on the surface of the casting, making it excellent The physical and chemical properties deteriorate, the hardness increases, the plasticity and elasticity decrease, and the brittleness increases.
The density of pure titanium rods and titanium alloy rods is smaller, so the inertia of liquid titanium flow is smaller. Titanium liquid has poor fluidity, resulting in low casting flow. There is a big difference between the casting temperature and the mold temperature (300 degrees), and the cooling is fast. Casting is carried out under a protective atmosphere. Defects such as pores will inevitably appear on the surface and inside of titanium castings, which have a great impact on the quality of the castings.
Therefore, the surface treatment of pure titanium rods and titanium alloy rods is more important than other titanium products. Due to the unique physical and chemical properties of titanium rods, such as low thermal conductivity, low surface hardness, low elastic modulus, high viscosity, low electrical conductivity, easy oxidation, etc., this brings great difficulties to the surface treatment of titanium. It is difficult to achieve the best results using conventional surface treatment methods. Special processing methods and operating methods must be adopted.