Generally, cemented carbides (WC-Co) that consist of tungsten carbides and cobalt are used for cutting tools. But since cemented carbides are made of import dependent rare metal, reuse and recycling are required. If cylindrical shanks that the cutting edges are cut off can be combined, it is possible to reuse those shanks as new cutting tools. But in this case, the joining strength of brazing method tends to be rather weak for being used as cutting tools. Instead of the brazing method, the diffusion bonding will be expected with the high strength and the small deformation. Many studies on the diffusion bonding were reported, but there were few studies on the diffusion bonding of cemented carbides.
In this study, a potential for applying the diffusion bonding of carbides was investigated. So the effect of the bonding condition on the bending strength, the microstructure of the bonding line and the distribution of tungsten and cobalt were examined. As a result, the strength of the diffusion bonding was higher than that of the brazing at higher than 1100°C, and at 1200°C, it was almost the same as the base metal's strength. Cemented carbides were successfully joined by the diffusion bonding.
