The Depletion and Retention Characteristics of PFPE Lubricants and X1P on Magnetic Media

The depletion and retention characteristics of magnetic thin film rigid disks coated with PFPE lubricants and X1P additive were investigated in this study. The tribological performance was evaluated by a drag test with a waffle head sliding against the disk that was designed to mechanically wear out the lubricant layer. An IR beam was aligned on the test track to directly measure the amount of PFPE lubricants and X1P left on the media surfaces for determining the depletion and retention characteristics of the lubricants. The test results show that under ambient and hot/wet (60°C/80%RH) conditions the media coated with AM3001 have higher retention ratio on the test track than those coated with ZDOL2000. After the head sliding for 100 hours, about 40% AM3001 still remains on the test track, while almost no ZDOL2000 left. However, the X1P was observed to strongly anchor on the surface and not wear out as PFPE lubricants did. The retention characteristics of X1P are independent of lube combination, either AM or ZDOL lubricants. The data indicate that more than 60% of the original X1P remains on the test track under all test conditions. The remaining X1P is quite stable and does not decrease as the drag test time increases during the latter test stage. It is demonstrated that X1P exhibits a good antiwear property and excellent retention performance.