The heat-resistant and tribological mechanism of nano-Fe ₃ O ₄ –reinforced nitrile butadiene rubber

To improve the tribological properties of nitrile butadiene rubber (NBR), nano-Fe ₃ O ₄ particles with good lubricity were added into the NBR to prepare NBR/nano-Fe ₃ O ₄ composites. In our experiment, surface microstructure of the composites was observed by JSM-5600LV low-vacuum scanning electron microscope; disposition of nano-Fe ₃ O ₄ was measured by an energy dispersive x-ray spectrometer; friction and wear condition of the composites were tested by UMT-2MT friction testing machine, and friction condition of the composites were tested for different temperatures by SRV high temperature friction testing machine. The results showed that after adding nano-Fe ₃ O ₄ particles in NBR, surface of the composites was smoother than NBR due to less defects and the tribological properties were significantly improved. Friction and wear rate of the composites were 300% lower than NBR, and we owe this to the nano-Fe ₃ O ₄ particles that played a role as solid lubricant on the surface of the composites. Meanwhile, friction coefficient was greatly affected by friction time; when the friction time was more than 10 min, the friction coefficient would become larger and there would be more abrasion; the friction coefficient of the composites was less affected by the temperature with the additional increase in nano-Fe ₃ O ₄ particles.