Abstract: A hard crystal substrate such as a GaN substrate or a SiC substrate is polished by using polishing oil slurry having abrading particles of artificial diamond clusters dispersed in a dispersant. The artificial diamond clusters include approximately spherical agglomerate particles with average particle size D50 of 20 nm or more and 50 nm or less, having primary particles with particle diameters of 2 nm or more and 10 nm or less. A rough polishing process is carried out first such that an average surface roughness of 0.5 nm or more and 1 nm or less is obtained, followed by a finishing process such that the average surface roughness of said surface becomes 0.2 nm or less.

Abstract: A hard crystal substrate such as a GaN substrate or a SiC substrate is polished by using polishing oil slurry having abrading particles of artificial diamond clusters dispersed in a dispersant. The artificial diamond clusters include approximately spherical agglomerate particles with average particle size D50 of 20 nm or more and 50 nm or less, having primary particles with particle diameters of 2 nm or more and 10 nm or less. A rough polishing process is carried out first such that an average surface roughness of 0.5 nm or more and 1 nm or less is obtained, followed by a finishing process such that the average surface roughness of said surface becomes 0.2 nm or less.

Abstract: A hard crystal substrate such as a GaN substrate or a SiC substrate is polished by using polishing oil slurry having abrading particles of artificial diamond clusters dispersed in a dispersant. The artificial diamond clusters include approximately spherical agglomerate particles with average particle size D50 of 20 nm or more and 50 nm or less, having primary particles with particle diameters of 2 nm or more and 10 nm or less. A rough polishing process is carried out first such that an average surface roughness of 0.5 nm or more and 1 nm or less is obtained, followed by a finishing process such that the average surface roughness of said surface becomes 0.2 nm or less.

Abstract: A foamed polishing sheet for use in a free particle polishing method using abrading particles with average particle diameter less than 0.1 ?m is produced by applying a foaming paint of a foaming resin on a surface of a form-providing film such as a plastic film, foaming the foaming paint by a wet foaming method to form a foamed sheet on the surface of the form-providing film, and peeling off the foamed sheet from the form-providing film so as to form a polishing surface on the foamed sheet having the same shape as the surface of the form-providing film.

Abstract: A vehicle such as straddle type suitable for running on a rough has a front wheel, which is steered, disposed in front of a vehicle body frame and a rear wheel disposed to the rear side thereof. Such vehicle is provided with a vehicle body frame structure which comprises a front frame unit, a center frame unit, and a rear frame unit. These front and center and rear frame units are first assembled individually as a unit and then coupled together integrally as a vehicle body frame structure.

Abstract: A foamed polishing sheet for use in a free particle polishing method using abrading particles with average particle diameter less than 0.1 &mgr;m is produced by applying a foaming paint of a foaming resin on a surface of a form-providing film such as a plastic film, foaming the foaming paint by a wet foaming method to form a foamed sheet on the surface of the form-providing film, and peeling off the foamed sheet from the form-providing film so as to form a polishing surface on the foamed sheet having the same shape as the surface of the form-providing film.

Abstract: A vehicle such as straddle type suitable for running on a rough has a front wheel, which is steered, disposed in front of a vehicle body frame and a rear wheel disposed to the rear side thereof. Such vehicle is provided with a vehicle body frame structure which comprises a front frame unit, a center frame unit, and a rear frame unit. These front and center and rear frame units are first assembled individually as a unit and then coupled together integrally as a vehicle body frame structure.

Abstract: A mirror-finishing method embodying this invention, with which the above and other objects can be accomplished, may be characterized as comprising the step of supplying a solution containing hydroxyl groups on a target surface to be polished of a glass substrate while simultaneously pressing onto this target surface an elastic sponge material having abrading particles affixed therein and a plurality of indentations on a polishing surface thereof, and causing the substrate and the sponge material to move with respect to each other.