TRIBOLOGY OF DIFFERENT CERAMIC SLIDERS ON LUBRICATED THIN-FILM DISKS

Seventy percent straight-rail, taper-flat sliders were made from Al2O3 TiC, Mn . Zn ferrite, SiC, Si3N4 and ZrO2 and tested on lubricated th in-film disks. The tests involved low speed (0.44 m/s) continuous cont act drag testing at a fixed radius for a maximum of one million revolu tions or to disk failure. SiC did not cause the disk media to fail, ev en out to five million revolutions, and the friction force had consist ently low modulation throughout the test. Si3N4 did not cause any disk failures but exhibited higher friction force with more modulation. Al 2O3 TiC, Mn . Zn ferrite and ZrO2 exhibited high failure rates (>50%), even though the initial friction forces were low. The failure rates o f these ceramics can be explained by the catalytic activity of Al2O3, TiC, Fe2O3 and ZrO2 on the degradation of the disk lubricant. Another explanation is the localized surface oxidation of SiC and Si3N4 slider s resulted in a softer slider material exhibiting more wear, leading t o higher contact area and lower con tact stresses at the slider/disk i nterface.