Researchers 3D Print Tungsten Carbide at Record Hardness

A Breakthrough in Hard-Metal Printing

Researchers at Hiroshima University have successfully 3D printed tungsten carbide-cobalt, one of the hardest and most widely used materials in industrial cutting tools and wear-resistant parts. The printed material achieved a hardness above 1,400 Vickers Hardness, matching conventionally manufactured tungsten carbide while enabling much more complex geometries.

The team used a hot-wire laser process that gently softens the metal powder before deposition, rather than fully melting it. This approach preserves the material's crystalline structure and avoids the microcracking and residual stress that normally plague attempts to print tungsten carbide with conventional laser systems.

Why Tungsten Carbide Is So Hard to Print

Tungsten carbide-cobalt combines extreme hardness with high wear resistance, making it essential for mining equipment, precision cutting tools, and machine components that operate under constant friction. The same properties that make it useful also make it difficult to process. Conventional laser powder bed fusion delivers too much energy, causing grain growth and cracking. The Hiroshima team solved this by feeding a heated wire into the melt pool alongside the powder, raising the temperature incrementally and giving the material time to bond without thermal shock.

A thin nickel-based alloy interlayer between printed layers further reduced cracking and improved the bond strength. The result is a fully dense part with mechanical properties comparable to forged tungsten carbide.

What This Means for Manufacturing

Being able to 3D print tungsten carbide changes how expensive wear parts are produced. Traditional manufacturing requires machining from solid billets or using costly carbide-forming presses. Both approaches waste material and limit geometry to what can be machined or pressed. Additive manufacturing places metal only where it is needed, cutting raw material costs for high-value components.

Mining and automotive industries could see the biggest near-term impact. Drilling bits, rock-cutting tools, and valve seats are all candidates for redesigned tungsten carbide parts with internal channels or hybrid material gradients that cannot be produced any other way. The ability to print on commercial-grade equipment also lowers the barrier to entry compared to specialized powder-bed systems.

Scalability and Remaining Challenges

The Hiroshima team acknowledges that scaling to larger parts and more complex designs still requires refinement. Print speed, powder flow consistency, and process monitoring need further optimization before the technique moves into production environments. The research team is working with industrial partners to address these gaps, with a focus on repeatability and quality assurance protocols that manufacturing customers require.

Even in its current form, the proof of concept is significant. It demonstrates that the class of extremely hard, traditionally unmachinable metals can be printed with commercially viable equipment. If the process matures as expected, it could make advanced metal additive manufacturing accessible to sectors that have so far treated 3D printing as a prototyping curiosity rather than a production tool.