In recent years, researchers have found that micro-nano particles as lubricant additives can improve the lubricating properties, low-temperature fluidity and anti-wear properties of lubricants. The important thing is that the lubricating oil added with micro-nano particles is no longer a simple treatment of the lubricity of the oil in the lubrication process, but to improve the lubrication effect by changing the friction state between the two friction pairs during the friction process. The development of additives has important meanings. For solid additives, the spherical shape is undoubtedly the most rational shape, which can realize the transition from sliding friction to rolling friction, thereby reducing friction and surface wear to the greatest extent. According to the different lubrication mechanisms of lubricating oil additives, this article mainly reviews the preparation methods of spherical micro-nano particles in recent years and their applications as lubricating oil additives, and summarizes the main anti-wear and anti-friction mechanisms.
Preparation method of spherical micro-nano particle additive
There are many methods for preparing spherical micro-nano particle additives. The traditional methods include hydrothermal method, chemical precipitation method, sol-gel method, and the emerging laser irradiation method in recent years. The particles produced by different preparation methods have different structures, compositions and properties, so the lubricating properties shown as lubricant additives are also different
The hydrothermal method is a method of synthesizing sub-micron materials by heating and pressurizing the reaction system in a specific closed pressure vessel with an aqueous solution as the reaction medium, and performing a hydrothermal reaction in a relatively high temperature and high pressure environment. The hydrothermal method is widely used because of the fine synthetic powder and controllable morphology. Xie et al. used a hydrothermal synthesis method to successfully convert Zn+ into Zn0 in an alkaline environment.Experiments have shown that adding organic additive triethanolamine (TEA) and adjusting the concentration can control the morphology of zinc oxide particles, making it from a slender ellipse. The spherical shape becomes a quasi-spherical shape. SEM shows that the Zn particles are uniformly dispersed, with an average particle size of about 400m. The hydrothermal method is easy to introduce impurities such as additives during the synthesis process, which makes the product impure and requires a high temperature and high pressure environment, which is highly dependent on production equipment.
Preparation of spherical micro-nano particles and their lubrication mechanism as lubricant additives. , The first effective lubrication mechanism by adding micro particles is to change sliding friction into rolling friction, which is the micro bearing effect, which effectively reduces friction and wear.
Post time: Dec-25-2020