Scientists at Hiroshima University have developed a novel 3D printing technique that allows them to create parts from tungsten carbide–cobalt (WC–Co) — one of the hardest engineering materials — without sacrificing its industrial-grade hardness. tomshardware.com +2
The challenge with ultra-hard materials like tungsten carbide is that they tend to crack or decompose when fully melted during traditional additive manufacturing. The Hiroshima team solved this by using a method they call «softening not melting». They employed a hot-wire laser irradiation technique: a laser beam softens the cemented carbide rod just enough to allow layer-by-layer bonding, rather than fully melting it. To further improve adhesion between layers, the researchers inserted a nickel alloy-based middle layer. By carefully controlling the temperature (keeping it above the melting point for cobalt but below the threshold for grain growth, which would degrade hardness), they successfully produced defect-free samples. tomshardware.com +1
The resulting material achieved a hardness of over 1400 HV (Vickers hardness), placing it among the toughest materials used in industry, just below superhard substances like sapphire and diamond. This breakthrough could revolutionize manufacturing, as it allows for more precise deposition of WC–Co only where needed, significantly reducing waste of expensive raw materials. The researchers note that this «softening» approach has potential for other hard materials beyond cemented carbides. However, challenges like reducing cracking and enabling more complex shapes remain for further refinement.
About the Author
