| 摘要 |
PROBLEM TO BE SOLVED: To obtain a ceramic sintered compact having a high hardness and a high toughness and capable of manifesting high abrasion resistance and high fracture resistance for especially cutting cast iron at a high speed. SOLUTION: This highly tough ceramic-based sintered compact contains Al in an amount of 1.5-10 mol.% expressed in terms of Al2O3, any of carbides, nitrides and carbonitrides of Ti in an amount of 30-80 mol.% and the balance of silicon nitride and a group 3a element (RE) of the periodic table in an amount of 1-10 mol.% expressed in terms of RE2O3 and based on the silicon nitride and has 100-1,000 MPa compressive residual stress applied to the silicon nitride, 15-18 GPa Vickers hardness and 8-15 MPam1/2 value of fracture toughness. |
