电场环境下聚乙二醇在钢/钢界面的摩擦性能研究

Most industrial lubricating oils are insulating oils, and the friction performances of insulating oils have rarely been investigated in an electric environment. Therefore, a possible tribological model for ether-containing insulating oil is proposed to supplement the research in the field of frictional performances of insulating oils such as polyethylene glycols (PEGs) at the steel interface under external electric fields (EEFs). The results show that the EEFs greatly affected the friction performances of PEGs. The positive voltage leads to the increase in friction coefficient. Under the negative voltage conditions, there is an optimal working condition to make the PEGs show the optimal anti-friction performance, namely voltage−1.0V, PEG viscosity 53 mPa·s, sliding speed 100 mm/s, and normal load 2 N. The analysis results indicate that the lubrication state of PEG under −1.0 V is the mixed lubrication. The PEG adsorption film and the reduction in the amount of Fe_xO_y and FeOOH in the tribochemical film contributed to the improved friction performance under the negative voltage condition of −1.0 V. It has been demonstrated that the frictional performance of insulating oils is also affected by EEFs. A tribological model for insulating oils under EEFs is proposed, which enriches the lubrication theory under EEFs and provides new insights for the design and development of multifunctional lubricating materials under EEFs.