| 摘要 |
PROBLEM TO BE SOLVED: To obtain a ceramic sintered compact having high hardness and high toughness and capable of exhibiting high wear and chipping resistances particularly in the high-speed cutting of cast iron. SOLUTION: This ceramic sintered compact consists of 1.5-10 mol.% (expressed in terms of Al2O3) Al, 30-80 mol.% carbide, nitride or carbonitride of Ti and the balance silicon nitride with 1-10 mol.% (expressed in terms of RE2O3) group IIIa element (RE) of the periodic table based on the amt. of silicon nitride and has 8-15 MPam0.5 fracture toughness. When the mol contents of the Ti compd. and Al2O3 are represented by MTi and MAl, respectively, the ratio of MTi:MAl is preferably in the range of 80:20 to 98:2. |
