| 摘要 |
PURPOSE:To improve the adhesive strength of the coating film of a titled tool and to reduce the chipping during cutting in the stage of subjecting a superhard alloy of a base material to a high frequency heating treatment then to a coating treatment during cooling after sintering by executing sintering, heating and coating stages without exposure to the atmospheric air. CONSTITUTION:Powder 1 of mixed carbide metals is pressed 2 to a tool shape and is sintered 3. While it is in the state of about >=1,000 deg.C right after said sintering stage or during the course of cooling or just prior to the next coating stage, it is subjected to induction heating 4 by high frequecies for a short time, whereby the ridge lines of the tool are melted locally. Following to this, it is allowed to cool of itself down to around 1,000 deg.C, after which the tool is coated 5 and is removed to the outside of the furnace after cooling. In the entire stage from the insertion into the sintering furnace till the removal therefrom after the coating, the tool is kept unexposed to the atmospheric air. Here, >=1 kind selected from carbide, nitride, boride, and oxide of IVa, Va, VIa group metals as well as their solid solns. and mixtures and one or more kinds materials selected from such as Al2O3, AlN, Si3N4, SiC, B4C and the like are coated on the tool in >= layers. |
