Researchers develop 3D-printing method for ultra-hard tungsten-carbide alloy

Scientists at Hiroshima University have demonstrated a laser-hot-wire additive-manufacturing process that creates defect-free tungsten-carbide-cobalt parts with industrial-grade hardness while using less raw material.

Hiroshima University researchers introduced a hot-wire laser additive-manufacturing technique that builds tungsten-carbide-cobalt (WC-Co) by softening the alloy instead of melting it completely. By pre-heating the filler wire and directing a laser either ahead of or behind the growing part, they deposited material only where required, reducing raw-material consumption. The method initially produced some decomposition in one configuration, but adding a nickel-based middle layer and tightly controlling temperature yielded a defect-free product with Vickers hardness exceeding 1400 HV, comparable to conventional sintered carbide.

The study, published in the International Journal of Refractory Metals and Hard Materials, highlights the potential for more efficient manufacturing of wear-resistant tools while noting challenges such as crack mitigation and shaping intricate parts. Future efforts will focus on scaling the process, testing additional alloys, and fabricating practical cutting tools. The work involved collaboration with Mitsubishi Materials Hardmetal Corporation.