| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an aluminum alloy substrate for a magnetic disk, excellent in smoothness on a plated surface and capable of achieving increased capacity and increased density of a magnetic disc, and a method for producing the aluminum alloy substrate for a magnetic disk. <P>SOLUTION: The aluminum alloy substrate for a magnetic disk includes, by mass, 2.0-6.0% Mg, 0.005-0.15% Cu, 0.05-0.6% Zn, 0.01-0.3% Cr, 0.001-0.03% Si, 0.001-0.03% Fe, and the balance Al with impurities. In the aluminum alloy substrate, the number of an Al-Cu-Mg-Zn based intermetallic compound having a longest diameter of more than 1 μm is less than one per 0.2 mm<SP POS="POST">2</SP>. Hot rolling is performed on the aluminum alloy substrate such that a temperature at the completion of the hot rolling is 280-360°C and a difference of surface temperatures at a center of a substrate width and an end is within 30°C at the completion of the hot rolling. <P>COPYRIGHT: (C)2013,JPO&INPIT |
