Self-repairing Performance and Formation Mechanism of Self-repairing Layer of Natural Serpentine Powder as a Lubricating Oil Additive
天然蛇纹石粉体润滑油添加剂的自修复性能及自修复层形成机理研究

A RFT-III reciprocating friction and wear tester (pin-on-block contact mode) was used to investigate the self-repairing performance of oleic acid-surface-capped natural serpentine powder as a lubricating oil additive for steel-steel frictional pair. The microhardness of worn block surface was measured using a hardness meter. The morphology, elemental composition, and chemical state of typical elements on worn steel surfaces and cross-sections were analyzed by means of scanning electron microscopy, energy dispersive spectrometry; and the self-repairing mechanism of the surface-capped natural serpentine powder was explored. Results indicate that the surface-capped natural serpentine powder as a lubricating oil additive can greatly reduce the friction coefficient and wear rate of the steel-steel pair, which was attributed to the formation of a self-repairing layer with good friction-reducing and antiwear performance on worn steel surface viatribochemical reaction in the presence of the lubricating oil additive. The self-repairing layer was composed of densely packed nanoparticles with various sizes. It contained a large amount of Fe2O3 and amorphous graphite as well as a small amount of Fe, organic fragments, Si-containing organic compounds, and SiO2.