(北京科技大学 材料科学与工程学院，北京 100083)
摘 要: 采用密度泛函理论(DFT)计算轧制油中二烷基二硫代磷酸酯(DDE)分子的反应活性，建立DDE-铜表面稳定吸附构型；利用四球摩擦磨损试验机和四辊轧机分别考察DDE对轧制油摩擦学性能和润滑性能的影响；并通过X射线光电子能谱(XPS)对磨损实验后铜表面产物进行分析。结果表明：DDE是一种具有优异极压性能及良好抗磨减摩性能的铜轧制油添加剂，在基础油中添加0.05%(质量分数)DDE使得轧制油油膜强度pB达到588 N，比基础油的提高66.57%，同时摩擦因数与磨斑直径明显降低。其吸附本质是在DDE与铜表面摩擦过程中发生化学反应形成S、O与Cu的化合物，计算的吸附能达到225.80 kJ/mol，表明分子在Cu表面产生稳定的化学吸附。含0.05% DDE的轧制油在实际轧制过程中的最小可轧厚度为22 μm。
关键字: 铜；轧制油；吸附特性；润滑性能；吸附能
（School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The activity of dialkyldithiophosphate ester (DDE) was calculated based on DFT theory, and the stable adsorption configuration of molecule-copper surface was built. The effects of DDE on the tribological performances and lubrication properties were investigated using a four-ball wear tester and a 4-high rolling mill, respectively. And the compositions of surface attachments were analyzed with XPS. The results show that DDE exhibits excellent extreme pressure and anti-wear properties as additives. With 0.05% (mass fraction) DDE into base oil, the maximum non-seizure load (pB) reaches 588 N, increases by 66.57% compared with that of base oil. The calculated adsorption energy of DDE-Cu is 225.80 kJ/mol. It is indicating stable chemical adsorption generated by O, S element on Cu surface during the wear process. The friction coefficient and wear scar are obviously reduced, and the minimum rolling gauge decreases to 22 μm.
Key words: copper; rolling oil; adsorption characterization; lubrication property; adsorption energy
