Tribological Properties of Self-Lubricating Polymer-Steel Laminated Composites

摘要

Self-lubricating polymer-steel laminated composites (SLC) consisting of matrix zones and filled zones were fabricated by a laminating-bonding process. The matrix zones were silicon steel sheets and the filled zones were polymer matrix filled with MoS_2 and graphite, respectively. The control specimen was prepared by spraying a polymer composite coating on a GCr15 disc. The tribological properties of SLC were investigated using a ball-on-disc tribometer under different loads and frequencies. Compared to the control specimen, the friction coefficient and wear rate of SLC was reduced by 57% and threefold at 4 N and 6 Hz, respectively. In addition, the friction coefficient of SLC was low and stable under low reciprocating frequency, and it was high and fluctuating under high reciprocating frequency. In addition, the wear rate increased with increasing applied load and reciprocating frequency. Scanning electron microscopy (SEM) images show that the lubricating mechanism of SLC was that solid lubricants embedded in filled zones expanded and smeared a layer of transfer film on the sliding path to lubricate the surface. The thermal expansion of solid lubricants was simulated using ANSYS software with thermalstress coupling. The simulation results showed the maximum temperature of the filled zones was 130℃, and the maximum normal displacement of solid lubricants was approximately 10 μm. This confirmed that the solid lubricants expanded effectively by the aid of frictional heat.