Research Article

Preparation and Tribological Properties of Dual-Coated TiO2 Nanoparticles as Water-Based Lubricant Additives

Figure 8

AFM analysis of the worn surface of steel ball after four-ball test lubricated by the water with 1.6 vt.% TiO2 nanoparticles with ultrasonic washing for 5 minutes (a) height image; (b) phase image.
785680.fig.008a
(a)
785680.fig.008b
(b)