Synergistic tribological performance of a water based lubricant using graphene oxide and alumina hybrid nanoparticles as additives

Abstract

Graphene oxide (GO) and alumina (Al 2 O 3 ) nanoparticles were added in deionized water in order to synthesise a dimensionally integrated nanolubricant. Tribological tests were performed using an alloy/stainless steel contact pair. A 0.12 wt.% 1:1 GO-Al 2 O 3 lubricant produced 64% and 47% reductions in the COF as well as 63% and 60% improvements in the Ra compared with 0.06 wt.% Al 2 O 3 and 0.06 wt.% GO solutions. Analysis of the worn surface indicated that a thin film consisting of a layer of GO and a tribo-layer of Al 2 O 3 was formed during testing. The GO layer prevented the direct contact of surface asperities, leading to a low resistance to sliding, whilst the Al 2 O 3 tribo-layer acted as a load bearer to strengthen the GO layer.

A Comprehensive Review of Water-Based Nanolubricants

“…Over the past few years, much research has been conducted on graphene-based composites including GO/SiO 2 [19,83], GO/TiO 2 [84], and GO/Al 2 O 3 [21]. For example, Huang et al [19] synthesised GO/SiO 2 water-based lubricants by mechanical stirring the aqueous suspension at 25 • C for 30 min, followed by ultrasonic processing (450 W) for 60 min (on/off interval of 5 s) in a chilled water bath.…”

“…ZP test has been used in many studies to determine the size distribution and stability of water-based lubricants [63,90,93,95,111,170]. Figure 5 demonstrates a bar graph of the ZP (mV) vs. nanolubricant with 0.12 wt.% GO, 0.12 wt.% Al 2 O 3 , and 0.12 wt.% GO-Al 2 O 3 (1:1) suspension [21]. It can be seen that the GO-Al 2 O 3 lubricant exhibits comparatively higher ZP absolute value (40 mV) than Al 2 O 3 (30 mV) and GO lubricants (35 mV), signifying a greater level of stability.…”

“…Over the past decade, water-based nanolubricants have been emerging as promising eco-friendly lubricants by dispersing nanoadditives into water [12][13][14][15][16][17][18][19][20][21][22][23], which integrates superb cooling capacity of water with excellent lubricity contributed by the nanoadditives. The use of water-based nanolubricants not only provides protection against friction and wear between the tool and the workpiece, but also improves overall quality of the product, demonstrating a great potential in engineering applications, such as metal forming [24][25][26][27][28][29].…”

Water lubrication of graphene oxide-based materials

“…However, the reports proved that the interlayer slip resistance may be increased due to additional hydrogen bond between GO layers compared to grapheme [37]. Besides, when GO is modified by the rigid spherical and quasispherical nanoparticles [38,39], it can function as bearings and transform the sliding friction into rolling friction partly.…”

TRIBOMETRY: How is friction research quantified? A review

“…The type of contact it presents allows evaluating the phenomena of friction and wear between surfaces that are in sliding contact but only one of these present movements. Figure 7 shows a diagram of the tribometer used by [33], who carried out a study of the effect of graphene oxide and hybrid nanoparticles of alumina, as additives in water-based lubricants. The objective was to determine the nano additive that significantly reduced wear on elements subjected to sliding friction.…”