6 Things You Need to Know About Platinized Titanium Anodes (3)
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#3: Advantages of Platinized Titanium Anodes
Platinum has the advantages of electrochemical inertness, mechanical strength, workability, and favorable electrical conductivity. However, it is prohibitively expensive. The 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 can withstand 12 volts, beyond which the insulating barrier breaks down and current flow starts the corrosion process. As an example, the US submarine Seawolf has an automatic corrosion protection system based on platinum-plated anode. The use of platinum on titanium (or platinum on tantalum) anodes has enabled a CP system with reasonable current density and low cost, which protects the nuclear-powered submarine from deterioration on a long-term basis.
New ways to produce titanium anodes at a commercial scale and thin films of platinum on titanium anodes by vapor depositing, rolling, and plating have ensured superior and durable anodes at a reasonable cost.
These anodes allow moderate current densities without affecting the base metal. Platinum layers need not be free of pores to ensure effective performance. Low resistance between the electrode and aqueous media (e.g., seawater) ensures the formation of a durable oxide film on titanium as long as the voltage is maintained within a safe range. These anodes can be lightweight have a convenient size and shape, and ensure stability of operational voltage due to a low platinum consumption rate per ampere-hour.
In hard chrome plating applications, platinum on titanium anodes are environmentally friendly because they are lead-free. They maintain their geometrical shape for almost three years, ensure low downtime, and pose a lower employee health risk because there is no lead chromate to be disposed of. Energy losses are lower with platinum-titanium anodes compared to lead anodes.
While lead anodes must be rods and sheets, platinum on titanium anodes can be made in T or U shapes, cylinders, or plates, based upon the geometrical shapes of the parts to be plated.
The consumption rate of platinum on platinized titanium anodes is low and proportionate to the current flow. In the case of deep well groundbed applications (for land-based oil and gas wells) the platinized titanium anodes are an easily manageable, non-brittle alternative to magnetite or graphite anodes, because they come with small diameter hole, thus also saving the deep drilling expense.
Overall benefits of using platinized titanium anodes include:
A low consumption rate that conserves precious platinum
Favorable dimensional stability
Corrosion resistance ensures durability with easy maintainability
Lightweight, as well as favorable current distribution in electroplating
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