Platinum Clad Anodes for Cathodic Protection by Anomet Products

Anomet Products is the leader in platinum clad anodes (platinized anodes). If you know the type of anode you are interested in, select it from the links at the top of this page. If you are unsure about the type of anode you need, please use the guides below. 

Leadership in Platinum Anode Technology

Anomet Products has been manufacturing platinum clad anode materials since 1976, and today is the leading supplier of platinum clad anode materials. Anomet, together with its sister company, Supercon, represents umatched experience in innovative metallurgical processing. Since its inception, Anomet has been dedicated to improving product quality and to developing new products using advanced metallurgical technology to provide long lasting cost effective anode materials. Today, Anomet is recognized throughout the cathodic protection industry for its product quality and excellent service.

Platinum Clad Anode Material Selection

The materials chosen in the design of Anomet's anodes are based primarily on the technical merits of the metals utilized. While the list of possible material combinations is virtually unlimited, the current standard line of Anomet material limits itself to those materials which possess specific properties necessary in the design of an effective impressed current anode material.

Platinum is used on the surface as a primary anode material due to its excellent corrosion resistance under anodic conditions coupled with its ability to pass current in all electrolytes without forming an insulating film. The corrosion resistance of platinum manifests itself in its low consumption rate. Its major disadvantage is its high cost, thus making it clear that it is most desirable to use as little platinum as is necessary. In order to restrict the amount of platinum used and to maintain an anode of some structural integrity, it is necessary to use some type of substrate material.

Included among the properties of the substrate should be the ability to form an insulating film under anodic conditions, such that a dimensionally stable anode is obtained, good conductivity, and relatively low cost. As there are no individual materials which fully meet all of these criteria, it is necessary in most cases to use a combination of materials.

Both niobium and titanium have the ability to form insulating oxide films under anodic conditions, and both possess unique advantages and disadvantages as a substrate for platinum. The major advantage of titanium is its low cost, particularly when considering its lower density. Unfortunately, there are many applications where the disadvantages of titanium far outweigh its cost advantage. First, in environments with high chloride contents, the insulating oxide film formed by titanium tends to break down, thus undermining dimensional stability needed for complete platinum consumption. A second disadvantage of titanium is its poor conductivity; approximately 5 times less than niobium and 50 times less than copper. Low conductivity makes titanium poorly suited for long wire lengths and restricts its use to larger diameter, shorter anodes.

The use of niobium as a substrate to platinum eliminates many of the problems with titanium. The breakdown voltage of niobium oxide film is approximately 120 volts in most commonly found cathodic protection environments. Although its conductivity is higher than that of titanium, it is often still too low for use in small diameters and long lengths. The principal disadvantage of niobium, however, is its relatively high cost.

Copper is an ideal conductor at virtually any length and diameter suitable for cathodic protection. The combination of high conductivity and low cost allows copper to be an ideal candidate for use in the design of an anode material.

Table 1: Material Considerations in Platinum Anode Design 
  

In reviewing the properties of these materials (Table 1), it becomes quite clear that if a combination of these materials was developed which exploits only the advantages, the result would be a superior anode material. The most logical combination of materials would include the use of a platinum outer layer, very thin due to cost, a layer of niobium beneath the platinum to allow for a dimensionally stable anode, and a copper core for both conductivity and economy. The niobium layer should be heavy enough to withstand normal mechanical handling.

To properly manufacture an anode material which is composed of multilayers, sophisticated metallurgical processing techniques must be employed to insure integral contact between the metal layers. The ideal method of insuring this contact is by providing a metallurgical bond. All of Anomet's clad materials are manufactured through very tightly controlled metallurgical coprocessing techniques yielding complete metallurgical bonds. In obtaining this type of high integrity bonding, three materials then behave as one with no possibility of spalling or non-bonds. This method of fabrication used by Anomet insures that the corrosion engineer obtains a high quality anode material.