中国科学院材料磨损与防护重点实验室/先进润滑与防护材料研究发展中心知识库

Influence of nanometer lanthanum fluoride (nano-LaF₃) on the tribological behaviors of polytetrafluoroethylene (PTFE) bonded solid lubricating coatings were investigated using a ring-on-block friction-wear tester under dry friction and RP-3 jet fuel lubrication conditions. The worn surfaces and transfer films formed on the counterpart steel rings were observed by scanning electron microscope (SEM) and optical microscope (OM), respectively. The microstructures of the nano-LaF₃ modified coatings and the distribution states of nano-LaF₃ were studied by field-emission scanning electron microscope (FESEM) and transmission electron microscopy (TEM), respectively. The results show that incorporation of nano-LaF₃ improves the microhardness and the friction-reduced and anti-wear abilities of PTFE bonded solid lubricating coatings. The wear life of the modified coating is about 6 times longer than that of the coating without nano-LaF₃ filler at a relatively low applied load (200 N) and rotary speed (1000 rev/min) under dry friction condition. The friction coefficient and wear life of the modified coating decrease with increase of applied load under dry friction, but the friction coefficient has hardly any variation and wear life decreases under RP-3 jet fuel lubrication condition. In addition, the friction coefficient of the modified coating reduces with the rotary speed increasing under dry sliding but has little change under RP-3 lubrication, the wear life increases firstly and then decreases. The results indicated that the wear failure mechanism is dominated by applied load, which plays an important role in guidance of application of nano-LaF₃ modified PTFE bonded coating under different working environment.