Research on the Lubrication Characteristics and Grinding Performance of Magnetic Minimum Quantity Lubrication

To address the problems of excessive pollution, high cost and insufficient lubrication and cooling efficiency inherent in traditional grinding lubrication technologies, a magnetic field‐assisted magnetic fluid minimum quantity lubrication ( mf MQL) technology was proposed and its lubrication characteristics and grinding performance were investigated to provide a green and efficient solution for precision grinding. Firstly, the mf MQL experimental setup was constructed, and a stably dispersed Fe 3 O 4 nanofluid was prepared as the lubricant; the effects of different magnetic induction intensities on the contact angle, surface tension and dynamic viscosity of the nanofluid were explored. Subsequently, GCr15 die steel was selected as the workpiece material and the grinding performance of mf MQL was compared with that of traditional flood lubrication and conventional MQL. Finally, the lubrication mechanism of mf MQL was analyzed via X‐ray photoelectron spectroscopy (XPS). The results indicated that with the increase of magnetic induction intensity, the contact angle and surface tension of the Fe 3 O 4 nanofluid were decreased by approximately 33.3% and 45.6%, respectively, while the dynamic viscosity was increased by a maximum of 35.5%, which led to a significant enhancement in the wetting penetration and oil film load‐bearing capacity of the lubricant. Compared with conventional MQL, mf MQL with 120 mT reduced the grinding temperature, grinding force and workpiece surface roughness Ra value by approximately 36.4%, 67% and 46.4%, respectively, and increased the grinding wheel ratio by 53.2%, demonstrating superior comprehensive performance to traditional flood lubrication. Under the influence of the magnetic field, the wetting and penetration capabilities of the nanofluid are significantly improved, allowing more lubricant to infiltrate the machining zone and form a robust lubricating film, which exerts synergistic effects of friction reduction, wear resistance and polishing. This mf MQL technology integrates the advantages of environmental friendliness and high efficiency, providing a feasible strategy for the precision grinding of difficult‐to‐machine materials.