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.
Copper Tungsten’s Niche
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.
Copper Tungsten Foil
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.
Customization
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.