Stability, Viscosity, and Tribology Properties of Polyol Ester Oil-Based Biolubricant Filled with TEMPO-Oxidized Bacterial Cellulose Nanofiber

Figure 9

The SEM micrographs of wear scar width (distance between two white dash-dot lines) on the surface of grey cast iron disk after the friction test using (a) PO, (b) N1S2, (c) N1S3, and (d) N2S4. Brown arrows indicate black pits.

(a)

(b)

(c)

(d)