改性纳米坡缕石在油润滑中的减摩抗磨性能研究

目的探索不同改性剂对纳米坡缕石的表面修饰效果,探究其在油润滑中的减摩抗磨和自修复机理。方法以油酸和钛酸酯作为改性剂对纳米坡缕石进行表面修饰,采用沉降法和透射电子显微镜(TEM)表征改性效果。将选择的改性剂和纳米坡缕石放入球磨机内在线修饰,制备成润滑油添加剂并将其超声分散于纯基础油150N中,形成润滑油分散体系。采用环-盘式摩擦磨损试验机对其摩擦性能进行考察,通过金相显微镜、扫描电子显微镜(SEM)、能量色散谱仪(EDS)进行微观结构观察与分析,并探究其润滑及自修复机理。结果采用油酸修饰的纳米坡缕石满足润滑油行业的要求,可显著改善润滑油的摩擦学性能。与纯基础油相比,当添加剂含量为3.0%时,45#钢摩擦副磨损表面形成了一层含多种元素的复合陶瓷自修复膜,平均摩擦系数降低了31.3%,磨损量减少了16.0%。结论纳米坡缕石添加剂可随油液流动智能吸附于摩擦界面,阻止摩擦副之间的直接接触,产生纳米滚珠效应。同时,随着界面滑动发生摩擦化学反应生成自修复膜,填补犁沟和划痕,在纳米滚珠和自修复膜共同作用下达到减摩抗磨的效果。

Anti-friction and Anti-wear Performance of Modified Nano-palygorskite in Oil

The work aims to investigate the modification effects of different modifiers on nano-palygorskite surface and explore their anti-friction and anti-wear performance and self-repairing mechanism in oil lubrication. Oleic acid and titanate were selected as the modifiers to modify the nano-palygorskite and the modification effect was evaluated by sedimentation experiments and transmission electron microscope (TEM). The pre-selected modifier and the nano-palygorskite were put in a ball millfor online modification to prepare lubricating oil additive. Then the nano-palygorskite additive was dispersed into base oil 150N through ultrasonic treatment to obtain the final lubricating oil dispersion. After that, the tribological properties of nano-palygorskite additive were tested by a ring-on-disk tribometer. The microstructure was observed and analyzed by metallographic microscope, scanning electronic microscope (SEM) and energy dispersive spectrometry (EDS), and the lubrication and self-repairing mechanisms were also explored. The nano-palygorskite modified by oleic acid could meet the requirements of the lubricant industry and significantly improved the tribological performance of lubricating oil. Specially, when 3.0wt.% of nano-palygorskite additive was introduced, the average friction coefficient and wear mass loss of 45# steel friction pair were reduced by 31.3% and 16.0% respectively, due to the formation of multiple elements-based composite ceramic self-repairing films. Nano-palygorskite additive can be intelligently adsorbed to the frictional interface along with the flowing oil and generates a nano-ball effect by avoiding the direct contact between friction pairs. Simultaneously, the friction-induced furrows and scratches are also filled by the self-repairing films during the interface sliding process. The nano-ball effect and the self-repairing film can work together to achieve the excellent friction-reducing and wear-resisting effect.