Three-Dimensional Contact Mechanics Studies of Zdol Hard Disk Lubricants

This paper reports the results of a study of the dynamic 3-dimensional response between a diamond point probe and a commercial hard-disk overcoat/lubricant system. The specific overcoat was CNx with a thickness of 50 A. The lubricant layer was ZDOL with nominal thicknesses of 11 A and 24 A in unbonded and bonded conditions. The experiments were conducted with a constant lateral displacement oscillation in the z, x & y direction of 1 nm at a frequency of 125 Hz. Results of this study show that the bonded lubricant layer increases the lateral force required to maintain a constant lateral displacement oscillation compared to both the unlubricated CNx coating and the CNx coating with the unbonded lubricant.