PRODUCTION OF MAGNETIC DISK SUBSTRATE MADE OF TITANIUM

• Main Authors: SUENAGA HIROYOSHI, OMURA MASAKI, MORITA KENJI, OKANO YOKO, IDA IWAO, NAGASHIMA HITOSHI, SAKIYAMA TOSHIO
• Format: Patent
• Language: English
• Published: 03.09.1993
• Subjects: APPARATUS THEREFOR; CHEMISTRY; ELECTROFORMING; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; METALLURGY; PHYSICS; PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTIONOF COATINGS

PURPOSE:To enable the formation of a magnetic film having an excellent error characteristic by subjecting the surface of a blank material to chemical etching to remove the surface over a specified depth, then subjecting the fresh surface to an anodic oxidation treatment. CONSTITUTION:The surface of the blank material of the magnetic disk substrate made of titanium is subjected to the chemical etching and is removed down to >=2nm depth from the surface. The fresh surface is then subjected to the anodic oxidation treatment. The surface work-hardened layer is thus removed by the chemical etching without undergoing machining, by which the uniform anodized film is formed thereon. The formation of the magnetic film having the excellent error characteristic thereon is possible. The depth of the removal by the chemical etching may preferably be confined to 200nm. A DC negative voltage ranging from-2 to-25V is preferably applied to the blank material of the magnetic disk substrate made of the titanium.