Rod-like brazed diamond tool fabricated by supersonic-frequency induction brazing with Cu-based brazing alloy

• Induction-brazing was used to fabricate a rod-like brazed diamond tool.
• Liquid brazing alloys do not drop.
• Metallurgical bonding occurs on the surface of the diamond grits.
• Low falloff percentage of the brazed diamond grits in a boring test.

Supersonic-frequency induction heating was used to fabricate a rod-like diamond tool brazed with a Cu-based brazing alloy in order to control the dropping of liquid brazing alloys that takes place in other brazing technologies. The brazing alloy can be spread evenly and the diamond grits can be correctly exposed on the rod-like brazed diamond tool by using a proper induction brazing technique. Dissolution, diffusion, and chemical recombination took place between the diamond grits and the brazing alloy, and a diffusion band approximately 30 μm wide was observed between the brazing alloy and the steel substrate. This demonstrates that metallurgical bonding occurred both at the interface of the diamond grits and the brazing alloy and at the interface of the brazing alloy and the steel substrate. A boring test of the brazed diamond drill showed that the total grain fracture percentage of the diamond grits was higher than the falloff percentage.