| 摘要 |
PROBLEM TO BE SOLVED: To provide an aluminum alloy substrate for a magnetic disk, even in the case the substrate is produced using an aluminum alloy with low purity comprising relatively large quantities of impurities such as Fe and Si, whose surface has high lubricity. SOLUTION: The aluminum alloy substrate for a magnetic disk has a composition comprising, by mass, 0.1 to 0.35% Cr, 3.0 to 6.0% Mg, 0.005 to 0.05% Fe and 0.005 to 0.05% Si, further comprising at least one or more kinds of metals selected from 0.01 to 0.2% Cu and 0.01 to <0.4% Zn, and the balance Al with inevitable impurities. The Cr content and Si content satisfy expression of (Cr mass%≥5×Si mass%), further, the maximum length of Al-Fe based intermetallic compounds is≤7μm, and the maximum length of Mg-Si based intermetallic compounds is≤4μm. COPYRIGHT: (C)2005,JPO&NCIPI
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