Aluminum alloy substrate for magnetic recording medium and method for manufacturing the same, substrate for magnetic recording medium, magnetic recording medium, and hard disc drive
AssigneeShowa Denko K.K.
InventorsTakenori Hashimoto, Wataru Sato
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Abstract
This aluminum alloy substrate for a magnetic recording medium has a metal structure made of an Al alloy having a composition including Si in a range of 18.0% by mass to 22.0% by mass, Fe in a range of 4.0% by mass to 6.0% by mass, Cu in a range of 2.5% by mass to 4.0% by mass, and Mg in a range of 0.8% by mass to 1.5% by mass with a remainder being Al, a primary-crystal Si precipitate having a maximum diameter of 0.5 μm or more and an average particle diameter of 2 μm or less is dispersed in the metal structure, a diameter is in a range of 53 mm to 97 mm, and a thickness is in a range of 0.2 mm to 0.9 mm.
Claims13
An aluminum alloy substrate for a magnetic recording medium, having
- a metal structure made of an Al alloy which has a composition including Si in a range of 18.0% by mass to 22.0% by mass, Fe in a range of 4.0% by mass to 6.0% by mass, Cu in a range of 2.5% by mass to 4.0% by mass, and Mg in a range of 0.8% by mass to 1.5% by mass with a remainder being Al,
- wherein primary-crystal Si particles which have a maximum diameter of 0.5 μm or more and an average particle diameter of 2 μm or less are dispersed in the metal structure, and
- a diameter of the substrates is in a range of 53 mm to 97 mm, and a thickness of the substrates is in a range of 0.2 mm to 0.9 mm, and
- a value of E/ρ (E:
- Young's modulus, ρ:
- density) is 35.0 (GPa)/(gcm−3) or more.
Dependencies are inferred from the claim text.