Nanoindentation and the tribology of head-disk interface components

Nanoindentation data are presented for three different but interrelated components of the thin film disk magnetic recording system-the air bearing slider/recording head, the disk substrate, and the sputter deposited thin film disk recording medium. Hardness traces across the slider trailing edge demonstrate the hardness of the NiFe, sputtered Al/sub 2/O/sub 3/, and the ceramic Al/sub 2/O/sub 3//TiC are 8, 10 and 24-40 GPa, respectively. Lapping under non-optimum, aggressive conditions can lead to significant recession in these components which is directly related to their hardness. The hardness and modulus have been measured for a number of alternate substrate materials ranging from AlMg/NiP to glass and glass ceramic. The ability of these substrates to resist damage from slider shock forces is presented and generally increases with substrate hardness, although other criteria (fracture toughness and plasticity initiation) rue required to rationalize all the data. Finally, hardness and modulus of carbon overcoat films are presented which have been sputtered under various conditions. The process variations lead to variations in hardness, the hardness/modulus (H/E) parameter, and tribological performance in slider/disk testing. The applicability of these mechanical property parameters to the wear degradation is discussed.