Tribo-Charge of Diamond-Like Carbon (DLC) Contact at Slider Disk Interface and Tribo Current Flow Through Disk DLC

This paper reports an experimental investigation on tribo-charging of diamond-like carbon (DLC) at the slider-disk interface and tribo-current flow through disk DLC. Measurements of the tribo-current are in three regimes-slider flying and touch down during disk deceleration, slider dragging on disk surface, and slider takeoff and flying during disk acceleration. Comparisons are made for tribo-charge currents at different disk initial linear velocities. It is observed that the tribo-current appears earlier with larger amplitude for a disk with larger initial velocities. During disk constant velocity phase, tribo-current ripple was observed while the slider is dragging on the disk surface due to intermittent slider/disk interactions. Despite having the same constant velocity, the equilibrium level of the ripple is different and depends on the disk initial velocity. Additional tribo-voltage and acoustic emission measurements were performed and compared with the tribo-current measurement to provide more insight to the tribo-charging process.