On improved durability characteristics for a Co-Cr flexible disk system

The signal durability of a disk which was formed by sputtering Co-Cr, permalloy, and inorganic protective layers on both surfaces of a flexible substrate was studied by evaluating its tribological characteristics. Out-put signal loss in proportion to head-pass number was found to be due to brittle fracture and/or plastic deformation of the disk. A disk with plastic deformation showed better signal durability than that with brittle fracture. High toughness and homogeneous structure of metal layers presumably improve durability for the practical use of a Co=Cr layered flexible disk system.