BLANK MATERIAL FOR MAGNETIC DISK AND METHOD OF MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a blank material for a magnetic disk comprising an aluminum alloy having the component of an oxide film with superior workability such as cutting and plating properties, and to provide a method of manufacturing the same. SOLUTION: In the blank material for the magnetic disk which includes the aluminum alloy containing 3.0 to 6.0 mass% of Mg and in which the balance is Al and inevitable impurities, the molar ratio Mg/AlO of Mg included in the oxide film formed on the surface after a pressure annealing to Al (hereinafter referred to as AlO) bonded to oxygen included in the oxide film is 1.0 to 5.0. The thickness of the oxide film is preferably 80 nm or less. As the manufacturing method, the condition upon the pressure annealing after press working is controlled so that the value of Mg/AlO is controlled. COPYRIGHT: (C)2010,JPO&INPIT