纳米铜润滑油添加剂的摩擦学特性及其自修复机理

为了评价纳米铜添加剂对摩擦副的减摩和自修复性能,采用液相化学还原法合成了二烷基二硫代磷酸(HDDP)修饰纳米铜微粒,利用四球摩擦磨损试验机分析了不同载荷条件下纳米铜添加量对摩擦系数、磨斑直径等摩擦学性能影响,采用扫描电镜(SEM)和X射线光电子能谱仪(XPS)分析了磨痕形貌及其化学成分组成,并通过纳米压痕测试技术测量铜膜硬度及弹性模量。结果表明:纳米铜添加量为0.4%(质量分数)时减摩效果最佳,磨斑直径和摩擦系数明显下降,比未添加纳米铜的降低了23.0%~27.2%和15.1%~24.9%。摩擦过程中纳米铜微粒在摩擦表面形成化学沉积膜,铜膜的纳米硬度为1.63 GPa,弹性模量为78.08 GPa,表现出优良的抗磨减摩性能。

Self-Repairing Mechanism and Tribological Properties of Nano-Cu as Lubricating Oil Additives

Cu nanoparticles coated with dialkyldithiophosphate were synthesized by chemical reduction in solution.The effects of the content of nano-Cu additives in base lubricating oil on the friction coefficient and wear scar diameters were investigated by four-ball machine under different loads.Moreover,scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) were used to study the wear scar images and elemental composition,and the hardness and elasticity modulus of the Cu film were tested by nano-indentation.Results showed that when the content of nano-Cu was 0.4％(mass fraction),the optimal anti-wear performance was obtained,and the friction coefficient and wear scar diameter were lower by 23.0％-27.2 ％ and 15.1％-24.9 ％ than those without nano-Cu additives,respectively.Furthermore,during friction process,the Cu nanoparticles were deposited on the frictional surface to form deposited film with hardness of 1.63 GPa and elasticity modulus of 78.08 GPa,which resulted in the excellent anti-wear and anti-friction performance.