摘要 |
A polishing composition for a magnetic disk, comprising alumina, water, a peroxide and an organic acid; a polishing process for a substrate to be polished, comprising the step of polishing the substrate to be polished with the polishing composition; and a process for manufacturing a substrate, comprising the step of polishing a substrate to be polished with the polishing composition. The polishing composition can be suitably used for the manufacture of a magnetic disk substrate for high-quality hard disks and the like. |