Abstract: A ceramics substrate for mounting a light-emitting element includes a ceramic sintered body, the ceramic sintered body having a mounting section on which a light-emitting element is mounted, in a surface portion on a mounting section side of the ceramic sintered body, a ratio of crystal grains having a crystal grain size of 0.2 ?m to 1.0 ?m in equivalent circle diameter being in a range of 45% to 80%, a ratio of crystal gains having a crystal grain size of 2.0 ?m to 6.0 ?m in equivalent circle diameter being in a range of 5% to 15%, and a ratio of crystal grains having a crystal grain size of more than 6.0 ?m in equivalent circle diameter being 2.7% or less.

Abstract: A ceramics substrate for mounting a light-emitting element includes a ceramic sintered body, the ceramic sintered body having a mounting section on which a light-emitting element is mounted, in a surface portion on a mounting section side of the ceramic sintered body, a ratio of crystal grains having a crystal grain size of 0.2 ?m to 1.0 ?m in equivalent circle diameter being in a range of 45% to 80%, a ratio of crystal gains having a crystal grain size of 2.0 ?m to 6.0 ?m in equivalent circle diameter being in a range of 5% to 15%, and a ratio of crystal grains having a crystal grain size of more than 6.0 ?m in equivalent circle diameter being 2.7% or less.

Abstract: The present invention provides an aluminum oxide-titanium nitride sintered body having good resistance to electrostatic damage and small variation in volume resistivity. The aluminum oxide-titanium nitride sintered body is mainly composed of 65 to 85% by weight of aluminum oxide and titanium nitride constituting the rest. The average of the sum of the crystal grain sizes of the aluminum oxide and the titanium nitride is 0.4 to 2.0 ?m. The aluminum oxide has a mean crystal grain size of 0.5 to 2.2 ?m and the titanium nitride has a mean crystal grain size of 0.2 to 1.6 ?m.

Abstract: The present invention provides sliding members respectively having sliding surfaces opposed to each other for creating dynamic pressure in a fluid, in which the sliding surfaces are formed of ceramics containing crystal grains of Al2O3, crystal grains of TiC contained in the crystal grains of Al2O3, and crystal grains of TiC existing independently of the crystal grains of Al2O3, and having a TiC content of 5 to 20 mass % in the total amount of Al2O3 and TiC, and the respective volume resistivity values R1 and R2 of the ceramics forming the sliding surfaces are within a range simultaneously satisfying equations (1) to (3) to prevent spark discharges from being induced between the sliding surfaces, and a fluid dynamic pressure bearing and a motor to which the configuration is applied: 106 ?·cm<R1?1012 ?·cm??(1) 106 ?·cm<R2?1012 ?·cm??(2) |R1?R2|?105 ?·cm??(3)

Abstract: The present invention provides an aluminum oxide-titanium nitride sintered body having good resistance to electrostatic damage and small variation in volume resistivity. The aluminum oxide-titanium nitride sintered body is mainly composed of 65 to 85% by weight of aluminum oxide and titanium nitride constituting the rest. The average of the sum of the crystal grain sizes of the aluminum oxide and the titanium nitride is 0.4 to 2.0 ?m. The aluminum oxide has a mean crystal grain size of 0.5 to 2.2 ?m and the titanium nitride has a mean crystal grain size of 0.2 to 1.6 ?m.

Abstract: The present invention provides sliding members respectively having sliding surfaces opposed to each other for creating dynamic pressure in a fluid, in which the sliding surfaces are formed of ceramics containing crystal grains of Al2O3, crystal grains of TiC contained in the crystal grains of Al2O3, and crystal grains of TiC existing independently of the crystal grains of Al2O3, and having a TiC content of 5 to 20 mass % in the total amount of Al2O3 and TiC, and the respective volume resistivity values R1 and R2 of the ceramics forming the sliding surfaces are within a range simultaneously satisfying equations (1) to (3) to prevent spark discharges from being induced between the sliding surfaces, and a fluid dynamic pressure bearing and a motor to which the configuration is applied: 106 ?·cm<R1?1012 ?·cm??(1) 106 ?·cm<R2?1012 ?·cm??(2) |R1?R2|?105 ?·cm??(3)