Surface treatment technology of titanium

Titanium is prone to react with elements such as O, H, N in the air and elements such as Si, Al, Mg in the embedded material at high temperatures, forming a surface pollution layer on the casting surface, which deteriorates its excellent physical and chemical properties, increases hardness, reduces plasticity and elasticity, and increases brittleness.

The density of titanium is small, so the inertia of titanium liquid flow is small, and the poor fluidity of molten titanium leads to low casting flow rate. The temperature difference between the casting temperature and the mold (300 ℃) is large, and the cooling is fast. Casting is carried out in a protective atmosphere, and defects such as pores are inevitable on the surface and inside of titanium castings, which have a significant impact on the quality of the castings.

Therefore, surface treatment of titanium castings is more important compared to other dental alloys. Due to the unique physical and chemical properties of titanium, such as low thermal conductivity, low surface hardness, low elastic modulus, high viscosity, low electrical conductivity, and easy oxidation, it poses great difficulties for surface treatment of titanium. Conventional surface treatment methods are difficult to achieve ideal results. Special processing methods and operating techniques must be employed.

The post surface treatment of castings is not only to obtain a smooth and shiny surface, reduce the accumulation and adhesion of food and plaque, maintain the balance of the patient's normal oral microbiota, but also to increase the aesthetic appeal of dentures; More importantly, through these surface treatments and modification processes, the surface properties and suitability of castings are improved, and the physical and chemical properties such as wear resistance, corrosion resistance, and stress fatigue resistance of dentures are enhanced.