Abstract: A sintered body and cutting tool, the sintered body (2) including: a first hard particle (10) containing TiCN; a second hard particle (20) containing (Ti, M) (C, N); a third hard particle (30) including a core portion (31) containing TiCN, and a peripheral portion (32) enclosing the core portion (31) and containing (Ti, M) (C, N) each as main components; a particle (40) containing at least one of Al, Zr, and Si; and a binding phase (50) containing at least one of Co and Ni and at least one of Re and Ru, and has a thickness of not greater than 5 nm. The third hard particle (30) has, in the core portion (31), a particle (33) containing at least one selected from Co, Ni, Re, and Ru, and has a dislocation (34) in each of the core portion (31) and the peripheral portion (32).

Abstract: Provided is a ceramic sintered body having high wear resistance and chipping resistance. Also provided are an insert, a cutting tool and a friction stir welding tool, each of which uses such a high-performance ceramic sintered body. The ceramic sintered body includes Al2O3 (alumina), WC (tungsten carbide) and ZrO2 (zirconia), wherein Zr (zirconium) element is present at either one or both of: (1) a grain boundary between crystal grains of the Al2O3; and (2) a grain boundary of crystal grains of the Al2O and crystal grains of the WC, wherein the ceramic sintered body contains 55.0 to 97.5 vol % of the WC, 0.1 to 18.0 vol % of the ZrO2, and the balance being the Al2O3, and wherein the ZrO2 is in a phase of tetragonal structure (T) or a mixed phase of tetragonal structure (T) and monoclinic structure (M).

Abstract: Provided is a ceramic sintered body having high wear resistance and chipping resistance. Also provided are an insert, a cutting tool and a friction stir welding tool, each of which uses such a high-performance ceramic sintered body. The ceramic sintered body includes Al2O3 (alumina), WC (tungsten carbide) and ZrO2 (zirconia), wherein Zr (zirconium) element is present at either one or both of: (1) a grain boundary between crystal grains of the Al2O3; and (2) a grain boundary of crystal grains of the Al2O and crystal grains of the WC, wherein the ceramic sintered body contains 55.0 to 97.5 vol % of the WC, 0.1 to 18.0 vol % of the ZrO2, and the balance being the Al2O3, and wherein the ZrO2 is in a phase of tetragonal structure (T) or a mixed phase of tetragonal structure (T) and monoclinic structure (M).