The tribological behavior of moving components and tooling in the automotive industry is a critical issue for improving tool life and increasing efficiency. This work discusses the effects of Zn and ZnO nanoparticle additives homogeneously dispersed within a metal-forming synthetic fluid at various filler fractions: 0.01, 0.05 and 0.10wt.%. Nanolubricants were evaluated under scuffing conditions at extreme pressures (EP) conditions using a four-ball tribotester in order to obtain the load-carrying capacity (poz) behavior, and overall tribological characteristics. This method has shown, with great precision, the influence of the nanofillers on the EP behavior of conventional lubricants. Worn surfaces were characterized through Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) to determine the tribological mechanisms of nanoparticles. An Alicona 3D surface measuring system was used for measuring the surface roughness of the wear scars. Both nanoparticles exhibited better friction-reducing and anti-wear properties compared to the base synthetic fluid. For Zn-based nanolubricants, an enhancement of ~180% in poz was obtained with 0.10wt.%, showing the effect of the spherical nanostructures that were tribosintered onto the surface due to the EPs of the test. Furthermore, the highest enhancement in poz (up to 250%) was achieved with incorporation of 0.10wt.% of ZnO demonstrating the potential of nanolubricants for improving the efficiency of mechanical components.

Abstract-This research focuses on the use of nanoparticles halloysite nanotube (HNTs) and montmorillonite (MONT) to improve lubricating properties of polyethylene glycol (PEG) for total knee arthroplasty (TKA). Tribological tests nanofluids under Tribotester T-02U were performed using the ASTM D4172 standard changing the test temperature at 36 ° C-37 ° C, the analysis was made from the coefficient of friction (COF) and diameter worn (WSD) provided by the inspection worn mark on the optical microscope Alicona. There was a clear reduction of COF by 27% at 0.05% HNTs and WSD by 10% at 0.1% HNTs. However in MONT implementation COF is reduced by 6% at 0.05% concentration and WSD 2% at 0.01% concentration. In conclusion we obtained that nanoparticles HNTs improve the properties of PEG in greater proportion than nanoparticles MONT, although emphasis on further studies in tribological applications in bioengineering industry with both materials, due to their biological and physicochemical properties, is made. Cytotoxicity tests that ensured the biocompatibility of the nanoparticles with C6 rat glioma cells were performed.