| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon nitride material cutter excellent in wear resistance and chipping resistance against thermal impact under wet environment. SOLUTION: This silicon nitride material cutter comprises a crystal phase having a silicon nitride material component containing βsilicon nitride and/or βsialon, a grain boundary having sintering assistant component, and hard particles having tungsten carbide of 900 Å or below in primary crystal grain diameter. At least in the flank of the silicon nitride material cutter, the ratio R in strength of the X-ray refraction peak of the β silicon nitride or a β sialon to the X-ray refraction peak of the tungsten carbide is 2<=R<=43. The total amount of 3A group element oxide and aluminum which are the components of the sintering assistant is 1.5 to 6 vol.% to the total 100 vol.% amount of the silicon nitride material component and sintering assistant component. The silicon nitride material cutter can provide excellent wear resistance, chipping resistance, and strength by having the configuration above. |
