电场环境下聚乙二醇在钢/钢界面的摩擦性能研究

Friction Performances of Polyethylene Glycols at Steel Interface under External Electric Fields

工业常用润滑油多为绝缘油,而针对绝缘油在电场环境下的摩擦性能研究较少。因此,提出一种含醚键绝缘油在电场环境下可能的减摩模型,以填补电场环境下绝缘油(如聚乙二醇(PEG))在钢/钢界面摩擦性能研究方面的空白。研究结果表明,电场对PEG的摩擦性能影响较大。正电压会导致摩擦因数增大;负电压条件下则存在一个最优工况使PEGs表现出最优的减摩性能,即电压-1.0 V、PEG黏度53 mPa·s、滑动速度100 mm/s和法向载荷2 N。分析结果表明在-1.0 V电压条件下PEG的润滑状态为混合润滑,其良好减摩性能主要归因于在接触表面形成的PEG吸附膜。此外,摩擦化学膜中Fe_(x)O_(y)和FeOOH总量的减少也有助于减摩性能的提升。证明绝缘油的摩擦性能同样受到电场环境影响,提出绝缘油在电场环境下的减摩模型,完善电场环境下的润滑理论,并为电场环境下多功能润滑材料的设计研发提供新思路。

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_(x)O_(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.