Surface Defect Handling of Titanium Plate and Rod

Pickling Surface Titanium Plate

Physical Mechanical Polishing

  • Sand blasting
    White corundum generally improves the sandblasting treatment of titanium wire.The sandblasting pressure is lower than that of non-precious metals, which is typically kept below 0.45MPa. Because when the injection pressure is too high, the impact of the sand on the titanium surface causes intense sparks. And the reaction of the temperature rise with the titanium surface can result in secondary pollution and impair the surface quality. It takes 15 to 30 seconds. On the titanium’s surface, only the slick sand, sintered layer, and part of the oxidized layer can be removed. It is important to swiftly eliminate the remaining reactive layer structure on the surface using chemical pickling.
  • Pickling
    Pickling is a rapid and effective way to totally remove the reactive layer without polluting the surface. Both the HF-HCl and the HF-HNO3 pickling solution can be used to pickle titanium. However, the HF-HNO3 solution has a greater capacity to absorb hydrogen than the HF-HCl solution, allowing it to adjust the concentration of HNO3 to lessen hydrogen absorption and perform surface polishing. HF concentrations are typically between 3% and 5%. HNO3 should be present in concentrations of 15% to 30%.
After sandblasting, the procedure of pickling can be used to completely remove the surface reaction layer of titanium plates and rods.

Chemical Polishing

By using chemicals to polish metal, the metal undergoes a REDOX reaction in the chemical media. Its benefits include the fact that all parts in contact with the polishing liquid are polished, regardless of the metal’s hardness, the polishing area, or the shape of the structure. It does not need specialized equipment and the operation is simple. It is suitable for complex titanium denture support structures. It is necessary to have a good polishing effect without compromising the precision of the denture since the process parameters of chemical polishing are challenging to control. The more effective titanium chemical polishing solution is made by mixing HF and HNO3 in a certain ratio. As a reducing agent, HF has the ability to dissolve titanium metal and level surfaces. HNO3 can generate a bright effect while also playing an oxidation role in the concentration of less than 10% to prevent excessive titanium dissolution and hydrogen absorption. High concentration, low temperature, and quick (1–2 minute) polishing times are required for titanium polishing solutions.

Electrolytic Polishing

Also known as electrochemical polishing or anodic dissolution polishing, titanium tubes have a low conductivity and exhibit strong oxidation, making it nearly impossible to polish titanium with water-based acidic electrolytes like HF-H3PO4 or HF-H2SO4. Additionally, after applying an external voltage, titanium anode immediately oxidizes, making it impossible to carry out anodic dissolution. Although anhydrous chloride electrolyte application at low voltage has a good polishing effect on titanium and tiny specimens can obtain mirror polishing, the goal of complete polishing still cannot be attained for complex restorations. This issue needs more research, but it might be resolved by adding cathode and altering the cathode’s form.

Scroll to Top