Micro/nanomechanical and tribological studies of bulk and thin-film materials used in magnetic recording heads

Micro/nanomechanical characterization of the bulk Al2O3-TiC and Ni-Zn ferrite, and thin films of Co-Zr-Ta and Al2O3 used in magnetic recording heads have been carried out. Hardness, elastic modulus and scratch resistance of these materials were measured by nanoindentation and microscratching using a nanoindenter. Fracture toughness was measured by indentation using cube corner and Vickers indenters. Friction and wear properties for these materials were measured using an accelerated ball-on-flat tribometer. Al2O3-TiC shows the highest hardness, elastic modulus and scratch resistance as well as the lowest wear damage, followed by the Ni-Zn ferrite, Al2O3 films, and Co-Zr-Ta film. The Co-Zr-Ta film exhibits the highest fracture toughness, followed by the Al2O3-TiC, Al2O3 films and Ni-Zn ferrite. There exists a good correlation between mechanical properties and wear damage. Higher mechanical properties result in less wear damage. In general, the bulk Al2O3-TiC and Ni-Zn ferrite show lower damage than the Co-Zr-Ta and Al2O3 films. For the thin films studied, the Al2O3 films show higher mechanical properties and less scratch and wear damage. (C) 2001 Elsevier Science B.V All rights reserved.