GLASS SUBSTRATE FOR MAGNETIC DISK AND METHOD FOR MANUFACTURING SAME

OF THE DISCLOSUREAbstractProblem to be Solved: To provide a glass substrate for magnetic disk having a principal face, the strength of which is further enhanced as compared to a case in which only a chemically strengthening method is used, and a method for manufacturing the same.Solution: A method for manufacturing a glass substrate for magnetic disk, which includes a forming process of press-forming a lump of molten glass using a pair of dies, wherein in the forming process, the cooling rate of the molten glass during pressing is controlled so that a first compressive stress layer is formed on a pair of principal faces of a glass blank that is press formed, and the method includes a chemically strengthening process for forming a second compressive stress layer on a pair of principal faces of a glass substrate formed using the glass blank after the forming process.Selected Drawing: FIG. 2