2007 年 73 巻 3 号 p. 345-349
For high efficiency production of high quality components, the high removal rate ultra-smoothness grinding method which can finish to almost the same smoothness formed by polishing is previously developed and ascertained to be useful for finishing to the surface roughness below 30nm (Rz) or 5nm (Ra). In the previous report, however, the surface flatness in the large area beyond 256μm square is not discussed. In the report, the influence of parallel step feed closely related to geometrical surface roughness on the surface flatness is examined by measuring the surface flatness of 4mm square and 50mm×40mm area together with the surface roughness of 256μm square. In the region of parallel step feed over the critical value the surface roughness becomes worse, which result is different from the geometrical surface roughness obtained from the concept of new ultra-smoothness grinding method. In the region of parallel step feed below the critical value, on the other hand, the slight undulation corresponding to the surface flatness of 4mm does not become better with the decrease of parallel step feed and is kept in a given constant value. The surface flatness of 50mm×40mm area formed by the grinding of silicon carbide is about 500nm (Rz) or 75nm (Ra) at two dimensional measurement though the surface roughness attains below 20nm (Rz) or 4nm (Ra) in 256μm square.