Friction Reduction and Lubrication Performance of New Microemulsion Cutting Fluid for AISI 1045

Abstract To address friction and wear issues in machining AISI 1045 steel, a novel oil-in-water microemulsion cutting fluid was developed using white oil, water, and eco-friendly additives (tricarboxylic acid and tall oil fatty acid amide). Tribological and lathe cutting experiments systematically evaluated its lubrication performance. The results show that the cutting fluid has a uniform and stable oil-in-water microemulsion structure, which is capable of forming a stable lubrication film. The dilution concentration had a significant effect on the lubricating properties of the cutting fluids, with the optimal lubrication achieved at the concentration of 10 wt%. At this concentration, more multilayer chemical lubrication films with low shear stress are formed. The load has the least impact on the friction coefficient, indicating that the cutting fluid can maintain stable lubrication even under high-pressure conditions. In practical machining, the cutting force is mainly affected by the feed rate and back engagement, while the surface roughness is mainly affected by the back engagement. This study provides a new option for reducing frictional wear during the machining of AISI 1045.