Influence of ZnO concentration in rapeseed oil on tribological behavior

Abstract

This paper presents results of testing the coarse rapeseed oil additivated with different concentrations of ZnO (0.25%wt, 0.50%wt and 1%wt, with 14±5 nm in size), on a four-ball machine. The test parameters were load on main shaft of the machine: 100 N, 200 N and 300 N and the rotational speed 1000 rpm, 1400 rpm and 1800 rpm. For the tested range of ZnO concentration, the value of 1%wt does not improve the friction coefficient, but the wear rate of wear scar diameter was lower than that obtained with the neat rapeseed oil and the values are less sensitive with load and sliding speed for the more severe regimes. The additivation of rapeseed oil with ZnO is still efficient for the tested range of load and speed as compared to neat rapeseed oil. The authors formulated lubricants using as dispersant (2-methoxyphenol) in the ratio 1:1 to the additive. The technology is at scale laboratory and implies mechanical stirring and sonication. The tribological behavior was analysed based on obtained results, by mapping the friction coefficient, the wear rate of the wear scar diameter and the final temperature in the oil bath. For the additivated lubricants the following conclusions could be drawn. Friction coefficient tends to reach 0.1 only for low speed and high load (v = 0.38 m/s and F = 300 N), wear rate of wear scar diameter decreases with the increase of load, for each tested speed, probably because of a full fluid film generation. For F = 250…300 N, the map reveals a poor dependence on the additive concentration. The final temperature in the lubricant bath depends on speed, but for the same speed, it depends less on load, having a maximum value for 0.75% nano additive. These conclusions underlined the necessity of testing the new formulated lubricants because additive concentration and regime parameters could have synergic influences on the tribological parameters.

Investigating the Impact of Fly-Ash Additive on Viscosity Reduction at Different Temperatures: A Comparative Analysis

“…Ionescu et al conducted a study to investigate the effectiveness of adding ZnO to rapeseed oil at various concentrations using a four-ball machine. [23]. They observed that adding 1 wt% ZnO did not improve the friction coefficient but reduced the wear rate compared to neat rapeseed oil.…”

Effectiveness of Lubricants and Fly Ash Additive on Surface Damage Resistance under ASTM Standard Operating Conditions

“…The application of nanotechnology to improve the tribological properties of lubricants gained increased interest in recent years. Various studies demonstrated that the addition of nanoparticles to lubricants can lead to a reduction in the coefficient of friction and wear rate, resulting in improved tribological performance [5][6][7][8][9][10][11][12]. Examples include the reduction in viscosity of lubricants depending on the density and size of micro-or nano-metal particles [5]; the micro-bearing effect at the friction interface of SiO 2 nanoparticles, leading to friction reduction [6]; and the development of eco-friendly oils with improved lubricity through adding SiO 2 nanoparticles to epoxidized Madhuca indica oil, resulting in a reduction in the coefficient of friction and wear rate [7].…”

“…Arumugam et al [9] compared the tribological properties of chemically modified rape-seed oil with two different anti-wear nano additives-TiO 2 and Al 2 O 3 -and found that the oil with spherical TiO 2 nanoparticles had a smoother worn pin surface and a lower friction coefficient. Ionescu et al [10] studied the effectiveness of adding ZnO to rape-seed oil and found that the wear rate decreased with 1%wt ZnO, while the authors developed a new lubricant using dispersant at a 1:1 ratio to the additive. The impact of CaCO 3 and SiO 2 nanoparticles on lithium-based grease was investigated by Razavi et al [11], and the authors found that the nanogreases prepared with CaCO 3 and SiO 2 nanoadditives showed improved physical, tribological, and rheological properties.…”

Analyzing the Impact of Fly Ash Additive Ratio on Lubricant Properties

“…Authors in [9] conducted a comparison of the tribological properties between chemically modified rapeseed oil and two distinct anti-wear nano additives, TiO 2 and Al 2 O 3 , using a pin-on-disc tribometer, and found that TiO 2 shows better friction properties than the oil with fibrous nano Al 2 O 3 wire [9]. Authors in [10] investigated the effect of adding ZnO to rapeseed oil at different concentrations on a four-ball machine and observed a reduction of the wear rate with an addition of 1%wt ZnO, although the friction coefficient remained unchanged. Authors in [11] studied the impact of CaCO 3 and SiO 2 particles on the properties of lithium-based grease, and found that the additives improved the properties of the original grease.…”