Enhanced Stability, Superior Anti-Corrosive, and Tribological Performance of Al2O3 Water-based Nanofluid Lubricants with Tannic Acid and Carboxymethyl Cellulose over SDBS as Surfactant

Abstract

In this research work, the stability, tribological, and corrosion properties of a water-based Al₂O₃ nanofluid (0.5 wt%) formulated with tannin acid (TA) and carboxymethyl cellulose (CMC) as dispersants or surfactants were investigated. For comparative purposes, sodium dodecylbenzene sulfonate (SDBS) was also incorporated. The stability of the nanofluid was assessed through zeta potential measurements and photo-capturing, revealing the effectiveness of TA and CMC in preventing nanoparticle agglomeration. Tribological properties were examined using a pin-on-disk apparatus, highlighting the tribofilm of Al₂O₃ that enhanced lubricating properties of the nanofluid by the SEM, resulting in reduced friction and wear of the contacting surfaces. Sample with the addition of both TA and CMC exhibited the best tribological performance, with a ~ 20% reduction in the friction coefficient and a 59% improvement in wear rate compared to neat nanofluid without TA and CMC_. Additionally, the corrosion resistance of the nanofluids were evaluated via weight loss and electrochemical impedance spectroscopy. The nanofluid sample containing both TA and CMC exhibited the lowest corrosion rate, with 97.6% improvement compared to sample without them. This study provides valuable insights into the potential applications of TA and CMC-based Al₂O₃ nanofluids as effective and environmentally friendly solutions for coolant or lubrication in cutting processes.

Keywords: Alumunium oxide; Carboxymethyl cellulose; Nanofluid; SDBS; Tannin acid.

Figure 1

Preparation procedure of the water-based nanofluid.

Figure 2

SEM image of Al₂O₃ nanoparticle.

Figure 3

FTIR full spectra (a), zoom between 3600–3100 (b), and 1700–1580 cm^-1 of all nanofluid samples.

Figure 4

Photo capturing stability observation of the nanofluids after preparation (a), after 24 (b), 96 (c), 168 (d), 264 (e), and 720 h.

Figure 5

Ball-on-disk tribological behavior of different nanofluid: CoF-sliding distance graph (a), and average CoF (b).

Figure 6

Wear rate and wear scar width of disk lubricated with nanofluids.

Figure 7

Surface topography and cross-section depth profile of wear scar on the disk lubricated by water (a), AO/SDBS (b), AO/TA (c), AO/CMC (d), and AO/TA/CMC (e).

Figure 8

The SEM–EDS analysis of the disk surface lubricated by AO/TA (a), AO/CMC (b), and AO/TA/CMC (c).

Figure 9

The EIS diagram (a), and Figures of Cu–Zn alloy surface after 3 days immersion (b).

Figure 10

EIS equivalent circuit diagram.

Figure 11

Schematic diagrams of lubrication and corrosion mechanism.