Tungsten carbide with cobalt, commonly known as WC-Co, is one of the hardest and most valuable engineering materials in the world. From drill bits to cutting tools, this cemented carbide keeps industries running. But shaping it has always been expensive and wasteful. Now, researchers at Hiroshima University in Japan have found a way to 3D print high-quality tungsten carbide parts, potentially transforming how manufacturers approach wear-resistant tools.

Why Tungsten Carbide Matters

WC-Co cemented carbides are everywhere in modern manufacturing. Their extraordinary hardness comes from tiny grains of tungsten carbide bonded together with cobalt. Traditional production involves pressing powders under extreme pressure and then sintering them in large furnaces. While effective, this process consumes enormous amounts of expensive raw material and struggles to create complex geometries.

Tungsten and cobalt are both critical minerals with limited global supply. China controls roughly 80% of global tungsten production, making supply chain resilience a growing concern for manufacturers worldwide. Any technology that reduces material waste directly addresses both cost and geopolitical risk.

The Breakthrough: Laser + Hot Wire 3D Printing

The Hiroshima team, led by Assistant Professor Keita Marumoto, took a fundamentally different approach. Instead of using metal powders — which often introduce pores and impurities — they fed solid sintered WC-Co rods into a laser-based additive manufacturing system. These rods already possessed the correct internal structure, eliminating many defects associated with powder-based methods.

The process combines a high-powered laser with a hot wire system. Electric current preheats the carbide rod before it reaches the laser zone, reducing the laser energy needed and limiting heat damage to the material. This “softening rather than fully melting” technique proved to be the key innovation.

Early experiments revealed challenges. One laser strategy caused pores and cracks as the carbide decomposed into weaker forms, including graphite. A second approach reduced chemical breakdown but introduced iron contamination from the steel base, softening the material.

The Nickel Buffer Layer Solution

The breakthrough came when researchers added a thin nickel-based alloy layer between the steel base and the carbide deposit. This buffer layer served two critical functions: it limited heat flow into the steel and blocked iron atoms from migrating upward into the carbide layer.

With this optimization, the process stabilized dramatically. The carbide rod softened without decomposing, and microscope analysis confirmed that the carbide grains remained small and structurally intact. Most importantly, the hardness reached approximately 1400 HV (Vickers hardness) near the surface — placing it among the hardest industrial materials, just below sapphire and diamond.

“Cemented carbides are extremely hard materials used for cutting tool edges and similar applications, but they are made from very expensive raw materials such as tungsten and cobalt, making reduction of material usage highly desirable,” said Marumoto. “By using additive manufacturing, cemented carbide can be deposited only where it is needed, thereby reducing material consumption.”

What This Means for Industry

The implications are significant for several sectors:

• Cutting tool manufacturing — Instead of machining carbide from large blocks, tools could be printed with carbide only on the cutting edge, saving material and reducing costs.
• Wear-resistant components — Mining, construction, and oil & gas industries rely on carbide-tipped parts that could benefit from on-demand, waste-minimized production.
• Multi-material parts — The ability to deposit carbide on tougher base metals opens possibilities for creating components with both hardness and structural flexibility.
• Supply chain resilience — Reducing tungsten and cobalt consumption per part lowers dependence on limited mineral resources.

The research also has broader implications beyond tungsten carbide. As Marumoto noted, “The approach of forming metal materials by softening them rather than fully melting them is novel, and it has the potential to be applied not only to cemented carbides but also to other materials.”

Remaining Challenges

The team acknowledges that cracking at the start of some builds remains an issue, likely due to thermal stress. They believe improved heat control during the initial layers could resolve this. Future work will explore more complex geometries and additional material combinations.

How TT3DPrint Can Help

At TT3DPrint, we specialize in FDM 3D printing for custom prototypes, educational models, and production parts. While tungsten carbide printing requires specialized metal AM systems, the broader trend of material-efficient 3D printing directly benefits the custom printing industry. Whether you need functional prototypes, educational models of industrial components, or custom parts for your business, our 220-machine Bambu Lab fleet delivers precision and reliability at scale.

Contact us to discuss your next project.

Conclusion

Hiroshima University’s achievement marks a significant step toward making tungsten carbide additive manufacturing commercially viable. By solving the long-standing challenges of decomposition, contamination, and structural integrity, this research opens the door to more sustainable and cost-effective production of some of the world’s hardest industrial materials. As the technology matures, we can expect to see 3D-printed carbide tools and components entering mainstream manufacturing within the next few years.

Sources: Hiroshima University via The Brighter Side, ScienceDaily, TechSpot