Preparation, characterisation and lubrication performances of Eu doped WO₃ nanoparticle reinforce Mn₃B₇O₁₃Cl as water‐based lubricant additive for laminated Cu‐Fe composite sheet during hot rolling

Abstract

Citric acid‐synthesised Eu‐doped WO3 (WO3:Eu3+) and Mn3B7O13Cl nanoparticles were characterised by X‐ray diffraction and transmission electron microscopy. The tribological properties of the Eu doped WO3 and Mn3B7O13Cl prepared as anti‐wear additives for enhanced lubrication were studied using a four‐ball tester. The experiment results indicated that Eu doped WO3 nanoparticle reinforce Mn3B7O13Cl has excellent load‐carrying capacity, wear‐resistance and friction‐reducing properties in water‐based lubricant, optimum concentration of WO3:Eu3+‐Mn3B7O13Cl was 0.5 wt%. The wear scar diameter decreased from 0.62 to 0.37 mm and the coefficient of friction was reduced from 0.083 to 0.065, which reductions are attributed to the nanotribofilms composed of B2O3, WO3, Fe2O3 and Eu2O, which prevented direct contact between metals. Hot rolling experiments of laminated Cu‐Fe composite sheet were carried out to study the effect of nano‐WO3:Eu3+‐Mn3B7O13Cl on surface qualities including topography of rolled strips. Results show that the surface topography becomes smooth with the addition of nanoparticles into water‐based lubricant, which is mainly attributed to the nanoparticles increase the viscosity of water‐based lubricant and the oil film to avoid the direct contact tribopair during hot rolling, thus reducing the friction coefficient and roll wear.

A Comprehensive Review of Water-Based Nanolubricants

“…Generally, a linear relationship exists between the NP concentration a tion intensity [166,176,177]. For instance, Liang et al [123] assessed NP sta absorbance method for 48 h and noted that the dispersion stability wa Mn3B7O13Cl-WO3:Eu 3+ from a linear graph (absorbance vs. time), as shown The results also showed that WO3: Eu 3+ and Mn3B7O13Cl exhibited a decre absorbance over time, indicating that NPs settled more rapidly in acidity that in alkalinity solution. Compared to Mn3B7O13Cl, Mn3B7O13Cl-WO3:Eu 3+ relative absorbance, thus presenting better stability.…”

“…While HO-BN the best dispersion stability due to the presence of more hydroxyl groups o is worth noting that at higher nanofluid concentration this method might n rately because the absorption range is outside the system's highest limit [17 Generally, a linear relationship exists between the NP concentration and the absorption intensity [166,176,177]. For instance, Liang et al [123] assessed NP stability using an absorbance method for 48 h and noted that the dispersion stability was obtained for Mn 3 B 7 O 13 Cl-WO 3 :Eu 3+ from a linear graph (absorbance vs. time), as shown in Figure 7a. The results also showed that WO 3 : Eu 3+ and Mn 3 B 7 O 13 Cl exhibited a decrease in relative absorbance over time, indicating that NPs settled more rapidly in acidity solution than that in alkalinity solution.…”

“…Multiple studies have mentioned the significance of protective film formation using NPs such as graphene based [73,75,77,134,145,147], ionic liquids [155][156][157], and phosphorus [162]. Some other NPs such as metal oxides [27][28][29][56][57][58], diamond [137], and composites [19,113,115,123] are also able to form a protective film on friction surfaces. Based on previous studies, it is concluded that the protective film not only reduces the friction and wear between friction pairs but also helps in isolating air, thus leading to reduced oxide scale thickness during hot steel rolling [27][28][29].…”