A Study on the Surfactant and Tribological Properties of Water-Based Nano-Rolling Lubricants on Non-Ferrous Metal Surfaces

This study proposes a composite-surfactant-assisted method for preparing Fe3O4 water-based nanolubricants to enhance environmental and tribological performance in rolling applications. The dispersion stability of nanoparticles in the suspension was analyzed. The optimal concentration of the nanolubricant was identified. In addition, the reaction mechanism between nanoparticles and water-based nanolubricants was discussed. The experimental results demonstrated that the lubricant containing 6 wt% Fe3O4 nanoparticles exhibited the best anti-friction and anti-wear performance. The aqueous lubricant with composite surfactants showed improved dispersion stability, with its Zeta potential increasing to −43.45 mV, and the intensity curve exhibited a single peak. Through contact angle measurements, wettability was also significantly improved. The molecular interactions of composite surfactants in the prepared water-based nanolubricants were investigated using numerical simulations. The water-based nanolubricant containing composite surfactants displayed enhanced adsorption capacity on Fe3O4 crystals. Compared to other surfactants, the Fe3O4 water-based nanolubricant prepared with composite surfactants exhibited stable dispersion properties. Therefore, composite surfactants can enhance the stability and wettability of water-based nanolubricants. This method enables the preparation of high-performance water-based rolling nanolubricants.