Tribological Properties Of Black Phosphorus Nanosheets As Lubricating Additives

Nearly half of the primary energy consumption on the earth is in the friction and wear links.When severe wear occurs,the failure of parts and the damage of mechanical equipment will also be accelerated.Lubrication is an important way to effectively reduce the wear of mechanical equipment and prolong the service life of equipment.In today's technology,adding nanoparticles to base oil to improve the lubrication performance of lubricating oil has become one of the important research directions of tribology researchers.Black phosphorus has a special layered structure.The combination of layers and layers depends on weak van der Waals force.It is easy to slip between layers and has good lubrication performance.Because of the high price of black phosphorus nanosheets,we urgently need to compound other lubricants with black phosphorus nanosheets to form new composite lubrication particles to reduce the cost of use and improve their lubrication performance under special conditions.In this paper,black phosphorus nanosheets were prepared by thermal solvent method,and composite particles were prepared by depositing titanium benzenesulfonate and titanium dioxide on the surface of black phosphorus nanosheets,and their tribological properties as lubricant additives were studied.Firstly,red phosphorus was transformed into black phosphorus by high energy ball milling,and then black phosphorus nanosheets were prepared by thermal solvent method using black phosphorus as raw material.Titanium Sulfonate/black phosphorus nanosheets?TiL₄/BP-ns?composite particles were successfully prepared by physical adsorption effect.Titanium dioxide/black phosphorus nanosheets?TiO₂/BP-ns?were prepared by sol-gel method.The prepared particles were dispersed in PAO6 base oil,and the lubrication properties of different particles in steel-steel friction pairs were studied.The results show that the black phosphorus nanosheets exhibit good lubrication performance under low load,mainly due to the interlayer slip of the black phosphorus nanosheets and the formation of friction reaction film on the friction surface.The TiO₂/BP-ns exhibits good lubrication performance.When the appropriate concentration of TiO₂/BP-ns is added,the wear pattern changes from severe abrasive wear to very slight abrasive wear,and the tribological mechanism can be attributed to the fact that the black phosphorus nanosheets exhibit In contrast,TiL₄/BP-ns exhibited friction reduction only under certain loads,and furrows on the worn surface were found to deepen by wear surface analysis.TiO₂ and BP-ns were combined with different theoretical mass ratios and then added to PAO6.The tribological properties of the friction pair in Si₃N₄-TC4alloy were studied by orthogonal test.The result show that the load was the greatest influence on the friction process of titanium alloy and the sliding speed followed behind load.The proportional was the third on the friction process and the concentration factor have the least impact.When TiO₂/BP-ns is added,the degree of adhesive wear on the worn surface is reduced.When the mass ratio of TiO₂ to BP-ns is 2:1,it shows better lubrication performance.The possible reason is that the composites with suitable mass ratio can form tribofilm which hard to be destroyed.