Tungsten carbide is used in many industries because of its superior hardness compared to tool steel and its exceptional toughness compared to technical ceramics. Given these superior properties, tungsten carbide is most often associated with tools used in metal cutting applications such as sawing, milling, and turning. Many are surprised to find that tungsten carbide is also frequently used in fluid dispensing or flow applications due to its excellent service life when exposed to corrosive wear. The improved wear resistance of tungsten carbide extends the component life of items such as nozzles in industries like waterjet cutting, oil and gas, and electronics. While many engineers designing these components are aware of the benefits of tungsten carbide, the challenges of manufacturing tungsten carbide components are less well-known.
First, it should be explained that tungsten carbide is the name used for a broad class of alloys that consist of actual tungsten carbide along with a metal binder and other added carbides (i.e., TiC and TaC). The two most common metal binders are cobalt and nickel. The metal binder affects hardness, toughness, and chemical compatibility. The metal binder content can range from 3% to 20% of the finished material, depending on the desired properties.
Tungsten carbide (WC) powder is produced by mixing tungsten carbide (WC) powder, a metal binder, and an organic binder in a solvent, then using a spray drying process to evaporate the solvent from the mixture. The powder is then compacted in a press, producing a green part with a strength roughly equivalent to a piece of chalk. While the green part is brittle, it can be machined using conventional turning, milling, and drilling techniques. Care must be taken when calculating the geometry, as the green part shrinks by up to 20% during sintering. Furthermore, at the temperatures during sintering (2500-2700°F), the part becomes relatively soft as the metal binder melts, and thin-walled areas may collapse. When removed from the sintering process, the part is in a hardened state. Moreover, due to the shrinkage rate, precise features cannot be created during green forming, meaning that complex and precise geometries must be added to the hardened part after sintering.
Unlike steel parts, tungsten carbide cannot be conventionally turned, drilled, milled, or welded in its hardened state. Instead, we were left with grinding and EDM processes, which are time-consuming, expensive, and have limited ability to create certain geometries.
This is where additive technologies like binder jetting and FDM can add value to customers by creating geometries previously unattainable in tungsten carbide. While there are challenges in manufacturing powders suitable for printing, progress is being made, bringing the well-known advantages of additives to the world of hard materials.
One example is the screw pump rotor (Moineau principle), whose geometry cannot be formed in green parts or ground in finished parts. With additive technology, pump designers can resist abrasive wear when pumping challenging liquids, thus having another material in their arsenal.
Another example is the creation of one-piece nozzles or spreaders for fluid dispensing, where curved fluid paths are preferred. Just a few years ago, these geometries were considered impossible to achieve in tungsten carbide, forcing engineers to choose suboptimal materials or less efficient geometries, both of which resulted in ongoing maintenance costs for customers.
Post time: Aug-04-2026