| 摘要 |
PROBLEM TO BE SOLVED: To provide an aluminum alloy sheet for magnetic disk hardly generating fine plated defects even when an acid etching treatment of a plating pretreatment is conducted under weak conditions.SOLUTION: The aluminum alloy sheet for magnetic disk contains 3.5 to 5.5 mass% of Mg, Fe limited to 0.025 mass% or less, Si limited to 0.020 mass% or less, 0.010 to 0.20 mass% of Cr, at least one of 0.010 to 0.1 mass% of Cu and 0.05 to 0.4 mass% of Zn, further 0.005 mass% or less of Mn and Ni limited to 0.001 mass% or less and the balance Al with inevitable impurities and having element component ratio in an Al-Fe-Mn-based intermetallic compound of 0.50 or less by a Mn/Fe ratio, element component ratio in an Al-Fe-Ni-based intermetallic compound of 0.20 or less by a Ni/Fe ratio, and absolute maximum length of an Al-Fe-based intermetallic compound of 10 μm or less. |
