The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 28, 2021
Filed:
Nov. 28, 2018
Uacj Corporation, Tokyo, JP;
Furukawa Electric Co., Ltd., Tokyo, JP;
Takuya Murata, Tokyo, JP;
Kotaro Kitawaki, Tokyo, JP;
Makoto Yonemitsu, Tokyo, JP;
Hideyuki Hatakeyama, Tokyo, JP;
Takashi Nakayama, Tokyo, JP;
Ryo Sakamoto, Tokyo, JP;
Hiroki Ota, Tokyo, JP;
UACJ CORPORATION, Tokyo, JP;
FURUKAWA ELECTRIC CO., LTD., Tokyo, JP;
Abstract
Provided are a magnetic disk and a method of fabricating the magnetic disk. The magnetic disk includes an aluminum alloy plate fabricated by a process involving a CC method and a compound removal process, and an electroless Ni—P plating layer disposed on the surface of the plate. The aluminum alloy plate is composed of an aluminum alloy containing 0.4 to 3.0 mass % (hereinafter abbreviated simply as '%') of Fe, 0.1% to 3.0% of Mn, 0.005% to 1.000% of Cu, 0.005% to 1.000% of Zn, with a balance of Al and unavoidable impurities. In the magnetic disk, the maximum amplitude of waviness in a wavelength range of 0.4 to 5.0 mm is 5 nm or less, and the maximum amplitude of waviness in a wavelength range of 0.08 to 0.45 mm is 1.5 nm or less.