摘要
目的提高润滑油在陶瓷摩擦副中的润滑性能。方法通过一步法制备银/聚多巴胺改性氧化石墨烯(Ag/PGO)纳米复合粒子,并作为润滑油的添加剂,通过摩擦试验研究含Ag/PGO润滑油的润滑性能。通过重力沉降法测试Ag/PGO在润滑油中的分散稳定性。观察磨痕微观形貌,通过分子动力学模拟方法,揭示含Ag/PGO润滑油的润滑机理。结果聚多巴胺改性氧化石墨烯(PGO)在润滑油中可以稳定分散25 d,Ag/PGO在润滑油中可以稳定分散10 d。含Ag/PGO润滑油在Si_(3)N_(4)/Si_(3)N_(4)、Si_(3)N_(4)/GCr15两种摩擦副中均表现出良好的润滑性能,含Ag/PGO润滑油在Si_(3)N_(4)/Si_(3)N_(4)摩擦副中的最佳质量分数为0.05%,与基础油相比,其摩擦因数和磨痕宽度分别降低了16.8%、17.6%;在Si_(3)N_(4)/GCr15摩擦副中的最佳质量分数为0.2%,其摩擦因数和磨痕宽度分别降低了53.6%、22.7%。表明含添加剂润滑油的磨痕表面质量得到提升。结论聚多巴胺经改性,可以有效提高氧化石墨烯在润滑油中的分散性能。与Si_(3)N_(4)壁面相比,含Ag/PGO的润滑油易于吸附在GCr15壁面。在剪切过程中,Ag/PGO与润滑油分子的相互作用减小了润滑油分子与摩擦壁面的相互作用能,减小了摩擦阻力,因此含Ag/PGO的润滑油在Si_(3)N_(4)/GCr15摩擦副中表现出更好的润滑性能。
According to the self-polymerization ability of dopamine in weak alkaline environment,silver/poly-dopamine modified graphene oxide(Ag/PGO)nanocomposites were prepared by one-step method as lubricating oil additives,and the dispersion stability of lubricating oil containing Ag/PGO and its lubrication properties in ceramic friction pairs were studied.Nano-composite particles doped with spherical metal Ag based on layered graphene structure had unique synergistic effect.On the one hand,spherical nanoparticles could enter graphene lamellae,which reduced the aggregation of graphene lamellae caused by van der Waals force attraction and improved the dispersion stability of Ag/PGO in lubricating oil.On the other hand,the layered graphene structure in Ag/PGO nanoparticles was more easily adsorbed on the friction surface,and the spherical nano-Ag particles entered the friction contact area under the friction to form support and ball bearing function,and the synergistic effect between the layered graphene structure and spherical nano-Ag improved the lubrication performance of lubricating oil.PGO could be stably dispersed in lubricating oil for 25 days and Ag/PGO could be stably dispersed in lubricating oil for 10 days.The best mass fraction of lubricating oil containing Ag/PGO in Si_(3)N_(4)/Si_(3)N_(4)friction pair was 0.05%,and the friction coefficient and wear mark width were reduced by 16.8%and 17.6%respectively.The optimum mass fraction of Si_(3)N_(4)/GCr15 friction pair was 0.2%,and the friction coefficient and wear mark width were reduced by 53.6%and 22.7%respectively.The worn surface of lubricating oil containing additives was characterized by scanning electron microscope and ultra-depth-of-field microscope.The results showed that the wear surface of base oil was basically the same as the matrix material,indicating that no friction protective film was formed,and the friction coefficient and wear width were the largest.Compared with other additives,the surface of wear scar containing Ag/PGO additive had black deposition layer and was relatively smooth,and irregular pits were alleviated,which showed that the adsorption film formed by Ag/PGO deposition had anti-wear effect.Based on Materials studio(MS)7.0 software,the molecular models of shear and adsorption of lubricating oil containing Ag/PGO in Si_(3)N_(4)/Si_(3)N_(4)and Si_(3)N_(4)/GCr15 friction pairs were constructed respectively,and the shear and adsorption properties of lubricating oil containing additives were simulated respectively,and the lubrication mechanism of lubricating oil containing Ag/PGO was studied.The results showed that the interaction between Ag/PGO nanoparticles and C16H34 molecules could reduce the adsorption between oil film and friction wall,and reduce the shear deformation and friction resistance of oil film.Through the synergistic effect of Ag nanoparticles and PGO,more C16H34 molecules were adsorbed on the walls of Si_(3)N_(4)and GCr15 with Ag/PGO nanoparticles,showing good adsorption performance.Compared with the wall of Si_(3)N_(4),the lubricating oil containing additives was more easily adsorbed on the wall of GCr15.Therefore,the lubricating oil containing Ag/PGO shows better lubrication performance in Si_(3)N_(4)/GCr15 friction pair.The lubrication mechanism of lubricating oil containing Ag/PGO is obtained,that is,through the synergistic effect of lubricating oil,nano-Ag and Ag/PGO nano-particle adsorption film,the lubricating oil containing Ag/PGO has the best lubrication performance in two kinds of friction pairs.
作者
尹振宇
张丽秀
李帅
张珂
李颂华
王俊海
王丽艳
YIN Zhenyu;ZHANG Lixiu;LI Shuai;ZHANG Ke;LI Songhua;WANG Junhai;WANG Liyan(School of Mechanical Engineering,Shenyang Jianzhu University,Shenyang 110168,China;Shenyang University of Technology,Shenyang 110870,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2024年第13期151-163,共13页
Surface Technology
基金
国家自然科学基金(52175107)
辽宁省应用基础研究计划(2022JH/101300234)
辽宁省教育厅项目(LJKZ0599)。
关键词
陶瓷摩擦副
聚多巴胺
摩擦性能
纳米复合材料
分散稳定性
分子动力学模拟
ceramic friction pair
polydopamine
friction performance
nanocomposites
dispersion stability
molecular dynamics simulation
作者简介
通信作者:张丽秀。
