Copper-Tungsten EDM Electrodes
What is Copper-Tungsten (Tungsten-Copper, CuW or WCu)?
Copper-tungsten is a pseudo-alloy of copper and tungsten. As copper and tungsten cannot form molecular bonds, bonding is achieved by infiltrating molten copper into a sintered matrix of tungsten powder. The resulting compound combines the characteristics of tungsten and copper. Copper-tungsten thus bridges the gap between tungsten carbide and brass and copper in electrical discharge machining. Many of the advantages and disadvantages of copper and tungsten are in opposition, so the combination of the two yields a material with few of the extreme characteristics of its parents.
Advantages of Copper-Tungsten
Copper-tungsten inherits a great deal of strength from tungsten, yet retains some of copper’s softness. Like tungsten carbide electrodes, it can be manufactured in the same very small sizes. Its strength also gives it stability, which decreases walking, and can reduce the need for meeting a blind hole, making it ideal for deep hole drilling. Unlike both copper and tungsten carbide electrodes, copper-tungsten is ideal for machining. It is yielding enough to accept machining, while strong enough to maintain its structure afterwards.
Copper-tungsten can effectively drill through many of the materials that are impractical targets for brass and copper. This is due to the mixture of tungsten. Though it cannot cost-effectively drill through the toughest materials, in much of the application overlap of tungsten-carbide and copper-tungsten, copper-tungsten is more economical. Copper-tungsten also has a shorter lead time than tungsten carbide, since its manufacturing process is simpler.
Disadvantages of Copper-Tungsten
The relative softness of copper-tungsten when compared to tungsten carbide and its greater expense than pure copper or brass contribute to copper-tungsten’s shortcomings. The softness of copper-tungsten prevent it from having the extremely tight tolerances of tungsten carbide. Greater softness and a higher electrical conductivity than tungsten-carbide also give copper-tungsten a correspondingly higher disintegration rate. Because of this, drilling into extremely hard materials with copper-tungsten is not cost-effective, even when considering the relatively high cost of tungsten carbide. Conversely, drilling into very soft materials often does not make sense because brass or copper will do the same job for less money.
Due to its unique mixture of characteristics, copper-tungsten comes up short in applications where the use of tungsten carbide, brass, or copper are obvious. However, when the solution to an EDM problem is ambiguous, copper-tungsten shines. If a material is a bit too tough for copper, and tungsten carbide seems like overkill, copper-tungsten is probably the right choice. If holes need to be drilled that are less than .1mm in diameter (micro hole drilling) in a soft material, copper-tungsten is also ideal. Copper-tungsten excels in the middle ground lying between copper and brass, and tungsten carbide.
Completely unique to copper-tungsten is its availability in foil form. This type of electrode opens up an entirely new spectrum of EDM applications. Please visit our copper-tungsten foil page for more information.
Custom copper-tungsten electrodes are available in sizes from .06mm (only rods are available from .06mm to .1mm) to 3.0mm in diameter, in lengths from 100mm to 700mm. Inner and outer diameters may be adjusted. The ratio of tungsten to copper can be adjusted to optimize electrode characteristics. The percentage of tungsten is from 50% to 90%, with 10% gradations. Diameter gradations for copper-tungsten are not as fine as those for brass or copper, due to different manufacturing methods.