(北京科技大學 材料科學與工程學院，北京 100083)
摘 要: 采用密度泛函理論(DFT)計算軋制油中二烷基二硫代磷酸酯(DDE)分子的反應活性，建立DDE-銅表面穩(wěn)定吸附構(gòu)型；利用四球摩擦磨損試驗機和四輥軋機分別考察DDE對軋制油摩擦學性能和潤滑性能的影響；并通過X射線光電子能譜(XPS)對磨損實驗后銅表面產(chǎn)物進行分析。結(jié)果表明：DDE是一種具有優(yōu)異極壓性能及良好抗磨減摩性能的銅軋制油添加劑，在基礎油中添加0.05%(質(zhì)量分數(shù))DDE使得軋制油油膜強度pB達到588 N，比基礎油的提高66.57%，同時摩擦因數(shù)與磨斑直徑明顯降低。其吸附本質(zhì)是在DDE與銅表面摩擦過程中發(fā)生化學反應形成S、O與Cu的化合物，計算的吸附能達到225.80 kJ/mol，表明分子在Cu表面產(chǎn)生穩(wěn)定的化學吸附。含0.05% DDE的軋制油在實際軋制過程中的最小可軋厚度為22 μm。
關鍵字: 銅；軋制油；吸附特性；潤滑性能；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
