Friction and durability of ceramic slider materials in contact with lubricated thin-film rigid disks

Slider materials with improved static and kinetic friction and durability of the head-disk interface are required for minimum separation between the head slider and magnetic medium and miniaturization of sliders. Mn-Zn ferrite, calcium titanate, Al2O3-TiC and SiC sliders were used in drag tests, stiction tests and contact start-stop (CSS) tests. The SIC slider exhibits the best tribological performance at all humidities as compared to other sliders. Relevant mechanisms are revealed with measurement of the contact angle of perfluoropolyether (PFPE) lubricants on slider materials, lubricant transfer tests, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infra-red (FTIR) analyses on the slider surfaces before and after tests. Best friction and wear performance of SIC is attributed to lubricant transfer from the lubricated disk to the slider surface and formation of tribochemical films. A lubricant layer on the slider surface protects the slider from wear and also increases the contact angle with the water film, resulting in a low meniscus contribution leading to low stiction. The tribochemical reaction forms a gel-like hydroxide layer on the SiC slider surface which performs as a boundary lubricant, leading to a low coefficient of friction and low wear.