| 摘要 |
PURPOSE:A composite cutting body which consists in sintering boron nitride and specific binder on a base plate under extra high pressure and high temp., then cutting this base plate to a sector shape and constituting the same to a cutting blade tip, and which is improved of its machinability and brazing characteristic. CONSTITUTION:Boron nitride of cubic system and/or wurtzite type is sintered together with a binder of specific carbide-metal under extra high pressure and high temp. in the central recess 4 provided to a platelike base plate 3 made of superhard alloy to form a polycrystalline sintered body 2, whereby the starting blank material 1 for the intended composite cutting body is prepared. Said sintered body 2 is formed of 40-95% boron nitride and the binder for the rest. This binder comprises TiC alone or comprises essentially TiC and contains one or more kinds of the carbide, nitride and boride of IV, V, VI group metals. Further, two groups besides the 1st group including Nb etc. are contained as metal components of less than the same amount as that of the component of said carbide. Said blank material 1 is cut out as a cutting blade tip 5 of a sector shape and is brazed into the notched step 7 of, for example, a cutting tool shank 6, whereby the intended composite cutting body is prepared. |
