| 摘要 |
A glass substrate for magnetic disks, obtained by chemical strengthening treatment of a glass consisting essentially of from 50 to 65 wt % of SiO2, from 5 to 15 wt % of Al2O3, from 2 to 7 wt % of Na2O, from 4 to 9 wt % of K2O, from 7 to 14 wt % of Na2O+K2O, from 12 to 25 wt % of MgO+CaO+SrO+BaO, and from 1 to 6 wt % of ZrO2. |
