To further identify the key lubrication modes within the system, FGO-CMMC (0.25CD) and FGO-CMMC (0.5CD) were also tested at 2N normal loads (~644 MPa maximum Hertzian contact pressure). Similar to the results seen at the lower load, FGO-CMMC (0.25CD) , achieves a stable, low friction performance throughout the test, maintaining a CoF < 0.2 until the test 500 μm ends (Figure ). In contrast, FGO-CMMC (0.5CD) showed evidence of coating failure at 2N sliding loads; the fatiguing of the solid lubricant initiates at ~ 2,700 revs, initially increasing the steady-state CoF to ~ 0.23, before gradual failure is observed after 4,000 revs, with μ increasing to > 0.4 by the end of the 10,000 revs test.