ALUMINUM ALLOY SUBSTRATE FOR MAGNETIC DISKS, AND MAGNETIC DISK INCLUDING THE SAME

• Main Authors: HATAKEYAMA HIDEYUKI, KOKUBUN YUMA, KITAWAKI KOTARO, KUMAGAI WATARU
• Format: Patent
• Language: English; Japanese
• Published: 09.03.2023
• Subjects: ALLOYS; CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS ANDNON-FERROUS ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; METALLURGY; PHYSICS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

To provide an aluminum alloy substrate for magnetic disks having excellent smoothness by reduction of undulation, and a magnetic disk including the same.SOLUTION: An aluminum alloy substrate for magnetic disks contains an aluminum alloy containing Mg: 3.50-4.50 mass% and Cr: 0.04-0.20 mass%, with the balance being Al and inevitable impurities. In the aluminum alloy, the distribution density of Al-Cr intermetallic compounds with a longest diameter of 0.01-1.00 μm is 1/0.001 mm2 or more.SELECTED DRAWING: None 【課題】うねりを低減することにより平滑性に優れた磁気ディスク用アルミニウム合金基板並びにこの磁気ディスク用アルミニウム合金基板を用いた磁気ディスクを提供する。【解決手段】磁気ディスク用アルミニウム合金基板は、Ｍｇ：３．５０～４．５０ｍａｓｓ％及びＣｒ：０．０４～０．２０ｍａｓｓ％を含有し、残部Ａｌ及び不可避的不純物からなるアルミニウム合金からなり、当該アルミニウム合金中において最長径０．０１～１．００μｍのＡｌ－Ｃｒ系金属間化合物の分布密度が１個／０．００１ｍｍ２以上である。【選択図】なし