Platinized titanium anodes synopsis
Titanium/Tantalum/Niobium-based platinum plated anode process, it using electroplating or brush plating or including coating process, the appearance is bright silver white, with the characteristics of large anode discharge current density and long service life.
Platinized titanium anodes synergistically combine the favorable electrochemical features of platinum (Pt) with the corrosion resistance and other characteristics of titanium. They are anodes normally produced by the electrochemical deposition of a very thin layer of platinum metal or the oxides of platinum onto a titanium substrate. These anodes operate as inert anodes with high durability and are preferred because they remain insoluble in common electrolytes.
Platinum is a precious metal known for its unique favorable attributes, including
- High resistance to corrosion
- Resistance to oxidation
- High electrical conductivity
- Ability to act as catalyst
- High chemical stability
- Capability to produce an excellent finish
The low consumption rate backed by high electrical conductivity makes platinum a preferred anode substance. But because of its high cost, only a thin layer of platinum is typically plated on different corrosion resistant materials such as tantalum (Ta), niobium (Nb) or titanium (Ti) to take advantage of these favorable features.
Platinized titanium anodes processing technology
By electroplating or brush plating process (including platinum coating sintering manufacturing process) the platinum metal on titanium (tantalum, niobium), a composite metallic coating can also be produced on the substrate. This composite consists of titanium metal, platinum, oxides of titanium and metallic compounds of titanium and platinum.
platinum coating sintering manufacturing process: we manufactures platinized titanium anode by adopting thermal decomposition process to get a dense wear-resistant layer of platinum coating. The anode surface is modified to improve adhesion of platinum and to significantly improve uniformity of coating thickness, also reduce the coating porosity imparting greater acid resistance to the anode. , The process of heat treating the composite coating produces changes in chemical composition and morphology that improves its electrochemical properties. This platinum coated titanium anode can be fabricated into bar, rod, sheet, mesh and other customized shape to meet your special needs.
Chemical behavior of platinized titanium anodes
Platinum is preferred on an anode’s outer surface because it is highly resistant to corrosion and can ensure current flow in most electrolyte media without leading to the formation of an insulating layer on itself. Because it doesn’t corrode, it doesn’t produce corrosion products and hence the consumption rate is very low.
Platinum is inert in fused salts and acids, whereas it is dissolved in aqua regia. There is no risk of hydrogen embrittlement. (You can learn about hydrogen embrittlement in the article An Introduction to Hydrogen Embrittlement.) It is one of the few rare metals that perfectly resist chlorides of seawater.
Titanium shows reasonably good resistance to a marine environment (seawater in particular). It does not react with concentrated (80%) solutions of metallic chlorides. However, it is susceptible to attack by hydrofluoric acid (HF)and hot hydrochloric acid (HCl) of higher concentrations. Even hydrogen peroxide and hot nitric acid can attack titanium. Oxidizing agents normally do not attack titanium because it readily forms a protective oxide coating. However, non-oxidizing substances such as sulfuric acid (above 5% concentration) and phosphoric acid (above 30%) can attack titanium. From a hydrogen embrittlement point of view, titanium fares better than tantalum as an anode material.
Advantages of platinized titanium anodes
Platinum has the advantages of electrochemical inertness, mechanical strength, workability and favorable electrical conductivity. However, it is prohibitively expensive. Development of platinum on titanium and platinum on tantalum (plated as well as cladded) materials has opened up the feasibility of using these for anode materials for metal finishing and cathodic protection systems in critical applications.
When used for anodes in aqueous media such as seawater, the titanium forms a stable layer of insulating oxide film on the surface that is stable below a certain breakdown voltage, thus preventing a current flow between the aqueous media and the anode. In the marine environment, the oxide formed on titanium is able to withstand 12 volts, beyond which the insulating barrier breaks down and current flow starts the corrosion process.
Features of platinized titanium anodes
- platinized titanium anodes geometry remains constant over time.
- Energy savings.
- High corrosion resistance.
- High dimensional stability and load resistance.
- High levels of adhesion of the precious metal coating.
- Improved resistance to acid attack.
- Increased throughput with reduced plating times.
- Light weight (especially the mesh grid anode).
- Long operating life; maintenance-free.
- Long service life under higher current density in acidic solutions.
- Produce complex shape of anode.
- Resistance to interface degradation by deposits.
Application of platinized titanium anodes
- Horizontal plating, pulse plating;
- Precious metal electroplating – e.g. Au, Pd, Rh and Ru baths;
- Non-ferrous metal electroplating – e.g. Ni, Cu, Sn, Zn and non-fluoride Cr baths;
- Printed circuit boards electroplating;
- Impressed Current Cathodic Protection.
We can produce platinized titanium (or Ta, Nb) anodes of plates, mesh, tubes, or to be customized according to customer requirements.