Aluminum alloy substrate for magnetic disk and manufacturing method thereof

The technology of an aluminum alloy substrate and manufacturing method is applied in the direction of the magnetic recording layer, the base layer of the recording layer, etc., which can solve the problems of preventing surface defects, increasing the number of rolling passes, and poor industrial production efficiency, and achieving thermal flatness Excellent stability, excellent impact resistance, excellent flatness effect

CN104109783BInactive Publication Date: 2016-11-23KOBE STEEL LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2016-11-23
Estimated Expiration
Not applicable · inactive patent

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Abstract

The present invention provides an aluminium alloy substrate used for a magnetic disc, and a method of manufacturing the same. The aluminium alloy substrate is resistant to impact, has great flatness, and has a plated surface with excellent smoothness. The aluminium alloy substrate is characterized by comprising the following aluminium alloys: below 0.03 by mass of Si, below 0.03 by mass of Fe, over 3.5 and below 4.5 by mass of Mg, below 0.2 by mass of Cr, and at least one selected from over 0.01 and below 0.20 by mass of Cu and over 0.01 and below 0.40 by mass of Zn, the balance being Al and unavoidable impurities, wherein the degree of flatness is less than 5 [mu]m, and the area rate of equiaxed grains on the surface of the substrate is less than 30%.
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Description

technical field

[0001] The present invention relates to an aluminum alloy substrate for a magnetic disk used as a substrate of a magnetic disk mounted in a hard disk drive such as a mobile personal computer, a notebook computer, and a portable audio player, and a method for manufacturing the same. Background technique

[0002] A hard disk drive (hereinafter, appropriately referred to as "HDD") has the following configuration: a magnetic disk formed on an annular disk, such as a magnetic film; a spindle motor that rotates the disk; and a magnetic head that reads and writes information on the disk. ; a swing arm that fixes the magnetic head to the front end; a voice coil motor connected to the base end of the swing arm.

[0003] In addition, as HDDs mounted on mobile devices such as mobile personal computers, notebook computers, and portable audio players, so-called 2.5-inch HDDs and HDDs smaller than 2.5 inches (hereinafter, appropriately referred to as “compact HDDs”) are us...

Examples

Embodiment Construction

[0035] Hereinafter, the form for carrying out the aluminum alloy substrate for magnetic discs of this invention, and its manufacturing method is demonstrated in detail.

[0036] [Aluminum alloy substrate for magnetic disk]

[0037] The aluminum alloy substrate for a magnetic disk of the present invention (hereinafter, appropriately referred to as an aluminum alloy substrate or a substrate) is characterized in that it is composed of an aluminum alloy that contains a predetermined amount of Si, Fe, Mg, and Cr, and contains a predetermined amount of Cu and at least one of Zn, the balance is composed of Al and unavoidable impurities, the flatness is not more than a predetermined value, and the area ratio of equiaxed grains on the substrate surface is not more than a predetermined value.

[0038] In addition, the aluminum alloy substrate for a magnetic disk of the present invention preferably has a yield strength greater than or equal to a predetermined value, and preferably has a ...