Since 1976, Anomet Products has been manufacturing platinum clad anode materials and is today an industry leader. Anomet, together with its parent company, Supercon, represents over 30 years 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.

Anomet's commitment to platinum clad anode materials does not stop at manufacturing, but continues on through research and development of existing and new materials. To better assist the cathodic protection industry, Anomet maintains an ongoing research effort to characterize the behavior and performance of its clad anode materials in cathodic protection environments. In addition to in-house laboratory testing, Anomet remains in close contact with its customers in order to accumulate data on existing field installations. With tens of thousands of anodes in service, this field data serves as a comprehensive guide to the performance of platinum clad anodes.

Through extensive experience, its research and development in the metallurgical and electrochemical fields, and excellent customer relations, Anomet has developed into a leading supplier of platinum clad anode materials.

MATERIALS SELECTION IN PLATINUM CLAD ANODES

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: Materials 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.

ANODE MATERIALS AVAILABLE FROM ANOMET

In order to provide faster service and greater economy, Anomet manufactures a number of "standard" anode configurations. These configurations (Table 2) are the result of several years of customer interaction, such that the anode designs could provide sufficient design flexibility for the engineer in a large variety of cathodic protection applications. An infinite number of materials combinations and thicknesses are possible, but in the majority of designs proper platinum thicknesses and diameters can be arrived at from Anomet's standard specification listing. For those applications where standard anodes may not quite fit, custom configurations are also available.

Table 2: Standard Product Specifications

** Double Platinum Thickness

Anomet 20

Anomet 20 is a standard anode material which is 20% niobium by crossectional area with a copper core. It is available as a stock item in both single and double platinum thicknesses (Table 2). The use of Anomet 20 is recommended for anode diameters of 1/8" and above. At these diameters, the niobium thickness is sufficient for most applications. Only where there are severe mechanical or unique handling concerns is a heavier niobium layer considered necessary.

Anomet 40

Anomet 40 is a standard anode material, which is 40% niobium by crossectional area with a copper core. The use of Anomet 40 is recommended for anode diameters below 1/8". The heavier niobium allows for sufficient mechanical and electrochemical protection of the copper core at these smaller diameters. Anomet 40 is sold principally at smaller diameters usually in double platinum thicknesses. It should be noted that anode life is not related to niobium thickness.

Anomet 100 Ti

Anomet 100Ti is a platinum clad anode material with a solid titanium core. It is available as a stock item in both single and 21/2 times platinum thicknesses. Titanium cored anodes are used where the lower breakdown voltage and anode conductivity are not of great concern. While smaller diameters are available, titanium is most often used in larger diameters of shorter lengths.

Tubular Anodes

Anomet's tubular anodes are designed for those applications where high anode surface area and high current output are required. Normally available in diameters of 3/4" and above, these anodes can be obtained fully or partially clad.

In previously available tubular anode designs, the principal disadvantage was the relatively heavy niobium wall thickness required to maintain structural integrity. The niobium often contributes more significantly to the cost than the platinum. Anomet's tubular anodes minimize this cost disadvantage by using a copper cored tubular substrate. That is, the substrate consists of niobium-copper-niobium, thereby utilizing 50-60% less niobium than a conventional solid tube. In addition to cost savings, excellent conductivity is achieved.

PartialClad Anodes

Partialclad platinum anodes were introduced as a technological innovation from Anomet, designed to provide the benefits of co-extruded metallurgically bonded materials to applications where platinum is needed to distribute current only on specific areas. Partialclad anodes find their greatest use in applications where it is necessary to have the current emitting surface stand off from the structure, such as in condenser water box walls. Table 3 provides typical configurations available. In many cases a steel core may be required in place of copper for increased mechanical strength.

Table 3: Typical Anode Specifications

Material Selection:
Anomet 100 Ti, Anomet 100 Nb, Anomet 20 Nb, Anomet 40 Nb.

Platinum/non-platinum area specified by customer.

Custom Configured Anodes and Special Products

For some applications Anomet's standard anode may not have the optimum configuration for certain design criteria or to meet a given set of specifications. In those cases, it is often necessary to manufacture to specific platinum thickness/anode diameter requirements. Anomet has full capabilities in custom design of anodes and has sufficient raw material inventories to respond rapidly to custom designs.

Included among the types of custom anodes Anomet has manufactured are steel cored anodes, solid niobium, solid tantalum, tantalum-niobium combinations, as well as a large variety of custom platinum and niobium thicknesses. The metallurgical and coprocessing expertise available at Anomet provides for virtually no restrictions on composite combinations.

As well as rod and wire anode geometries, Anomet provides platinum clad anode materials in sheet, strip, and woven mesh. Our woven mesh anode material is particularly unique in that it is manufactured by weaving platinum clad niobium wires in a mesh pattern yielding very high surface areas.

There is very little in the area of anode materials or geometry which does not fall in Anomet's capability. Part of Anomet's success has been the ability to turn customer ideas into practical, useful anode materials.

Platinum Clad Anode Construction

Complete metallurgical bond
Solid or copper cored niobium and titanium substrates
Platinum and niobium thicknesses can be optimized
Mechanical strength and ductibility
Steel core (optional) for added strength
Easy to transport and install
Available in various sizes and lengths

Platinum clad anodes by Anomet feature all the ingredients necessary for a long-life, cost-effective anode material. They offer a low consumption rate material metallurgically bonded to a corrosion resistant inert anodic oxide forming substrate with the flexibility of high conductivity or high-strength core materials.

Available in virtually any diameter and platinum thickness, Anomet's anodes are produced under strict quality control standards for long-term, trouble-free performance. Along with a quality product comes Anomet.s excellent service and quick delivery.