A Facile Method to Prepare Oil-soluble Nano-copper by Microemulsion and Its Tribological Perporties

摘要

The method of preparating the oil-soluble copper nanoparticles as lubricant additive was presented by chemical reduction in the microemulsion system of H2O/triethanolamine/Span-80/Tween-80/HL68. The copper nanoparticles are all global shap, with the diameter changing from 10 to 20 nm and a small partition of conglome- ration by means of transmission electron microscope (TEM). The friction and wear behavior of a steel-steel frictional pair under the lubrication of HL68 base oil containing nano-copper lubricant additive I6/HL68 was examined using a ring-on-disk test rig and a four-ball test rig. It is found that the introduction of the copper nanoparticles in the base oil led to a considerable decrease in the friction coefficient of the steel-steel contact. At the same time, the copper nano-particles' additive was also able to significantly increase the anti-wear ability and load-carrying capacity of the base oil. Namely, on one hand, both the wear mass loss of the friction pair and the wear scar diameter of the four ball pair were greatly decreased under the lubrication of the additive as compared to those under the lubrication of the base oil. On the other hand, the additive had a PB value as high as 755 N which is much larger than 588 N, that of the base oil. The perfectly tribological properties are probably attributed to the addition of copper nanoparticles, as the elastic microballoon sphere cells, which are prone to slip on high velocity and low-load condition as a result of the specific structure. While on low velocity and over-load condition, the load bearing and separate action of the copper nanoparticles are main factors.