Hiroshima University team uses hot-wire laser method to 3D print industrial-grade WC-Co

Researchers at Hiroshima University have developed a new 3D printing method for tungsten carbide–cobalt (WC–Co) that prevents cracking and damage that often occur with laser powder bed and other melting methods. The team uses a combination of additive manufacturing and a hot-wire laser setup, in which a laser works with a heated filler wire to improve material deposition while softening the material rather than fully melting it. The International Journal of Refractory Metals and Hard Materials will publish the work online in its April 2026 print issue.

According to the journal publication, the final products reached a hardness of over 1,400 HV without any visible holes or WC breakdown when the temperatures were kept above cobalt’s melting point but below the level that would cause excessive WC grain growth. A nickel-based interlayer further stabilized the microstructure. The group tested two different tool paths—one where the rod leads and one where the laser leads—and found that the rod-leading method was more likely to cause WC breakdown in the top layers, while the laser-leading method, along with the nickel interlayer and better temperature control, maintained high

Cemented carbides are tough materials used for cutting tool edges and similar applications, but they are made from very expensive raw materials, such as tungsten and cobalt, making reduced material usage highly desirable. By using additive manufacturing, cemented carbide can be deposited only where it is needed,” said Keita Marumoto in a university release.

WC–Co hardmetals are a mainstay for wear-intensive tooling but are typically shaped via powder metallurgy, a route that limits geometry and wastes costly feedstock. Previous studies on laser and binder-based additive manufacturing methods have shown common problems like cracking, loss of cobalt, and the formation of η-phase; using the soft-melting, hot-wire method is suggested to avoid these issues. The researchers indicate that near-term work will focus on crack management and more complex geometries, with eventual applications in cutting tools. Co-authors include collaborators from Mitsubishi Materials Hardmetal Corporation and Motomichi Yamamoto.