Tungsten is described as a ‘heavy metal’ due to its hard nature and corrosion resistance properties. It is a very dense metal and is used in a wide variety of industries ranging from radiation shielding to golf clubs. Working with Tungsten represents a challenge in several areas.
Tungsten is becoming harder to source and is listed as a conflict mineral. The UK government defies conflict minerals as “minerals mined in conditions of armed conflict and human rights abuses, and which are sold or traded by armed groups.” This has meant that full traceability will always be needed when sourcing Tungsten and this may result in longer lead times and increased costs.
As a ‘hard’ metal, Tungsten requires the right set up in order to machine it effectively. As Tungsten is hard and dense it is key during machining that vibration is minimized so as to avoid tool chipping. This means that the machine, spindle and tooling all need to be as rigid as possible. Machining of Tungsten requires sharper cutting tools and inserts such as CBD may be needed to avoid a lot of tool wear.
Tungsten requires greater cutting force and will often take a longer time to produce components. As best practice, Tungsten has similar machinability to Grey Cast iron.
The purity of the alloy affects the hardness of the material and its machinability. A purer alloy with be tougher than metals such as Titanium whereas Alloys with a lower percentage of Tungsten are similar to machining Stainless Steel. Experienced staff will be needed in order to ensure the best results.
One alternative to sourcing and machining in Tungsten would be to use Tungsten Carbide Coating. HVOF applied coatings have a very strong bond and are hard and dense in nature. These coatings are produced by taking a powdered material, in this case Tungsten and heating them up and ‘firing’ them out at extreme velocities where they liquify and impact the metal. These coatings allow you to use a much cheaper base material whilst still getting the same performance as using Tungsten.
Tungsten carbide coatings provide excellent wear, erosion and corrosion protection and are an alternative to Hard Chrome Plating. If you’re looking to get the benefits of using Tungsten without the negatives, then this might be the solution.
B&B are based in Huddersfield just off the M1 and can provide test pieces so that you can compare the performance of our coatings to your current process. Get in touch today for more about HVOF applied coatings. Email firstname.lastname@example.org or call 01484866386