(北京科技大学 材料科学与工程学院，北京 100083)
摘 要: 基于试验研究和理论计算从宏观和微观尺度揭示了分子结构对铝材轧制基础油摩擦学性能和铝表面吸附行为的影响。研究分别以异构烷烃煤制油(CTL)和正构烷烃白油(D100)为基础油，制备含不同浓度亚磷酸二丁酯(DP)的铝材轧制油，并采用四球摩擦磨损试验表征其摩擦学性能；基于量子化学计算和分子动力学模拟研究CTL、D100和DP的分子结构特征、吸附反应活性及在铝表面的吸附行为。结果表明：对于理化性能相近的CTL与D100，CTL的油膜强度(88 N)低于D100的(98 N)，但CTL对DP极压剂的敏感性更好。在同等DP浓度下，以CTL为基础油时，铝材轧制油具有更高的油膜强度，最大值为1050 N；而以D100为基础油时，油膜强度仅为981 N。理论研究表明：CTL和D100分子的最高占据轨道(HOMO)分布相同，均分布于整个分子碳链，但二者的最低空轨道(LUMO)分布不同，前者位于分子支链侧末端，而后者位于分子中心。CTL和D100分子均具有稳定的化学结构，且二者化学稳定性的差异较小；CTL和DP分子具有协同吸附作用，二者复配能显著促进轧制油体系在铝表面的吸附，并提高吸附膜稳定性。
关键字: 铝材轧制油；煤制油；摩擦；量子化学；分子动力学
（School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:In the present work, the effects of molecular structure on tribological properties and adsorption behaviors of aluminum rolling oil were revealed from macroscopic and microscopic scales by combining experimental research and theoretical calculations. Aluminum rolling-oil containing different concentrations of dibutyl phosphite (DP) were prepared by using coal-to-liquid (CTL) and traditional mineral oil (D100) as base oils, respectively. The tribological properties were characterized by four-ball tester. The molecular structure, adsorption activity and adsorption behavior of CTL, D100 and DP on aluminum surface were investigated based on quantum chemical calculation and molecular dynamics simulation. The results show that CTL with similar physical and chemical properties as D100, has a lower maximum non-seizure load of 88 N, but CTL is more sensitive to DP. When CTL is used as the base oil, aluminum rolling oil has a higher non-seizure load at the same DP concentration, the maximum value is 1050 N. Investigation results show that the highest occupied orbital (HOMO) distributions of CTL and D100 molecules are the same, distributing in the whole molecular carbon chain, but the lowest unoccupied orbital (LUMO) distribution is different, the former locates at the side end of the molecular branch chain, while the latter locates at the center of the molecule. Both CTL and D100 have stable chemical structures, and the difference of their chemical stability is also similar. In addition, CTL and DP molecules have synergistic adsorption effect, and the combination of CTL and DP molecules can significantly promote the adsorption activity of rolling-oil system on aluminum surface and improve the stability of adsorption film.
Key words: aluminum rolling oil; coal-to-liquid; tribology; quantum chemistry; molecular dynamics
