Surface Treatment of Titanium Materials

Surface Treatment Methods for Titanium Materials

Various surface treatment technologies are widely applied to titanium materials. Below is a clear classification of these methods:

Wear-resistant Surface Treatments:

• Wear resistance is a major challenge for titanium, making surface treatment particularly important.

• Wet plating: Includes Cr plating and Ni plating as effective wear-resistant methods. The electrolytic method of Ni plating followed by Cr plating offers fast film formation with thickness reaching several microns.

• Sputtering: Uses high-speed plasma jet to spray molten metal onto the material surface without vacuum, offering high efficiency.

• Surface strengthening methods: Including CVD, PVD, and PVCD technologies.

Anodizing:

• A mature process that forms dense oxide films on titanium surfaces, improving corrosion and wear resistance.

• Provides decorative effects while enhancing mechanical properties and insulation.

PVD Coating:

• Physical Vapor Deposition, a type of vacuum coating.

• Mainly used for functional coatings on titanium alloy surfaces, though durability needs improvement.

CNC Machining:

• Primarily used for shaping and finishing titanium alloys.

• Requires special tools like composite-coated cutters, diamond cutters, or CBN tools due to titanium's high hardness.

Thermal Diffusion:

• Methods like ion nitriding can nitride titanium surfaces to increase hardness.

• At 850°C, nitride film thickness increases from 0.7μm to 5.0μm, achieving surface hardness of 1200-1600Hv.

Electropolishing:

• Removes oxide films and contaminants from titanium surfaces through electrolysis, improving surface finish.

Liquid Phase Deposition:

• Example: Depositing bioceramic coatings on TC4 surfaces to add functionality.

Other Methods:

• Chemical plating, thermal spraying, low-pressure ion processes, electron/laser surface alloying, unbalanced magnetron sputtering, ion nitriding, ion plating, and nanotechnology.

In conclusion, titanium materials have diverse surface treatment methods, each with unique characteristics and applications. The appropriate method should be selected based on specific usage requirements and performance needs.