Diamond joined body, tool including the same, and method for manufacturing diamond joined body

摘要

A bonded diamond body (1) having a high bonded strength is provided. The bonded diamond body (1) includes a sintered polycrystalline diamond body (2), a hard substrate (3), and a hard layer (4) provided between the sintered polycrystalline diamond body (2) and the hard substrate (3), the sintered polycrystalline diamond body (2) containing a diamond grain and a sintering aid, the hard substrate (3) containing tungsten carbide and cobalt, and the hard layer (4) containing cobalt and a hard grain made of a carbide, a nitride, or a carbonitride having a Vickers hardness of 1100 Hv or more.