A breakthrough from Hiroshima University could change how some of the toughest industrial materials are made. Researchers have demonstrated a way to 3D print tungsten carbide–cobalt (WC–Co), a cemented carbide famous for extreme hardness that can rival sapphire and even diamond-like performance in demanding applications.
WC–Co is widely used across manufacturing because it holds up under intense wear, heat, and pressure. The downside is that its durability also makes it difficult and expensive to shape with conventional powder-metallurgy methods. Traditional approaches can require extensive machining and finishing, which increases production time while turning costly raw materials like tungsten and cobalt into wasted scrap.
The Hiroshima University team tackled that challenge with a technique called hot-wire laser irradiation. Instead of fully melting the material the way many additive manufacturing methods do, the process pairs a laser with a preheated filler wire. The goal is to soften and deposit the material in a controlled way, helping preserve the properties that make cemented carbides so valuable in the first place.
According to the researchers, the big advantage of 3D printing cemented carbide is efficiency: you can deposit the material only where it’s needed. That means lower material consumption, less waste, and potentially lower manufacturing costs for industries that rely on carbide parts and tooling.
Early experiments weren’t perfect. The team tested two fabrication orientations—rod-leading and laser-leading—and initially ran into problems such as defects and material decomposition. Their successful solution combined two key adjustments: adding a nickel alloy-based middle layer and carefully controlling temperatures to remain above cobalt’s melting point while staying below the threshold that would trigger problematic grain growth.
With those refinements, the researchers produced defect-free printed material with a hardness exceeding 1,400 HV, a level comparable to conventionally manufactured cemented carbides. That’s a notable result because hardness is one of the main reasons WC–Co is used for high-wear applications like cutting and machining.
Next, the team plans to further improve the process to prevent cracking and make it possible to print more complex geometries. If those efforts succeed, this hot-wire laser 3D printing approach could open the door to more efficient production of carbide cutting tools and other industrial components—delivering the same ultra-hard performance with far less waste of expensive materials.
