Choosing the Right Friction Modifier Will Directly Determine the Quality of the Lubricant

- Aug 03, 2020 -

Oil additives are an indispensable and essential component of lubricating oils, which are used to make up or improve the deficiencies of lubricating base oils and give them new properties. 

During the use of mechanical equipment, friction and wear often occur, which not only threatens the safety of the material but also causes enormous losses. There are two main ways to improve resistance and wear: under fluid lubrication or mixed lubrication conditions, improve the rheological properties of the lubricant to reduce shear stress; under mixed lubrication or boundary lubrication conditions, add a friction modifier to the grease to reduce the friction factor.

A friction modifier can better minimize wear. The mechanism is that when the metal surfaces that are in contact with each other mesh with each other due to load, local high temperature and high pressure will be generated. At this time, the antiwear agent reacts with the metal surface to form a reaction film with low shear strength. , To avoid direct contact between the two metal surfaces, play a role in reducing wear.

1.Ionic liquid friction modifier

Ionic liquids have the characteristics of extremely low volatility, good thermal stability, excellent viscosity-temperature performance, strong adsorption, etc. Under most working conditions, they can generate a boundary lubricant film on the surface of friction metal, which is an excellent performance modifier. . Dr. Liu's research group used ionic liquids in the field of tribology for the first time. Because of its excellent antiwear properties, the tribological properties of different types of ionic liquids have attracted full attention from researchers. Recent studies have shown that adding ionic liquids as friction modifiers to lubricating oils to improve their antiwear performance has good development prospects.

 Ionic liquids have excellent antiwear and anti-friction properties, which can effectively reduce the friction and wear of metal surfaces. Especially ammonium-based ionic liquids with flexible molecular structures can carry and convert more beneficial groups, so they are widely used. It is also a research hotspot.

 

2. Nanoparticle type friction modifier

Metal nanoparticles have small size effects and surface effects, which make them exhibit excellent antiwear performance, especially soft metal nanoparticles. Nano metal particles have more excellent antiwear properties than traditional friction modifiers because the nano surface is more comfortable to react on the metal surface to generate boundary lubrication. In recent years, researchers have done a lot of in-depth research on nanoparticle additives to solve a series of problems such as oil solubility, and found that whether it is a nano element, or its nitride, sulfur chemicals have excellent antiwear and anti-friction properties.

 

Nano-nitride, as a new type of dictionary modifier, can be embedded in the dents and pores on the metal surface under high temperatures and extreme pressure conditions to form a protective film. It is also possible to convert part of the sliding friction into rolling friction through the advantages of the nanoparticles' structure to further improve its antiwear performance.

 Nanoparticle antiwear agents have excellent tribological properties due to their structural advantages. Current research focuses on nano-element, nano-sulfide, nano-nitride, and nano-oxide. The screening of nanomaterials, the optimization of parameterization methods, and the improvement of modification methods will be the next research hotspots of nanoparticle friction modifiers.

 

3. Nitrogen-containing heterocyclic friction modifier

Nitrogen-containing heterocyclic compounds have good extreme pressure and antiwear properties, high thermal stability and good anti-oxidation and anti-corrosion properties, and have attracted extensive attention from researchers. C. Kajdas's "negative ion free radical" thought that the content of the N element in the nitrogen-containing heterocyclic additive will affect the resonance energy of the heterocyclic ring. As the content increases, the resonance energy decreases, thereby enhancing the activity of the friction reducer oil additive. It is easier to adsorb on the metal surface, and the antiwear performance is improved. During the friction process, the N element containing lone pairs of electrons undergoes a coordination reaction with some features on the surface of the friction pair, forming a reaction film of the nitrogen-containing heterocyclic metal complex, thereby reducing the wear on the cover of the friction pair.

The development trend of lubricating oil products is to extend the oil change period and improve fuel economy. The addition of friction modifiers can form a physical adsorption film or a chemical adsorption film on the friction surface, improve the lubrication condition of the friction pair, effectively reduce mechanical friction and wear, and reduce energy consumption.

Infomakis dedicated to the technology development of special oil additives, combined the Technology of nanomaterials developed dry lubricant and oil additives two series. Our products can significantly improve the performance of lubricating oil, improve energy efficiency, effectively protect the lubrication device and extend the oil change cycle, which can satisfy the lubrication oil constantly upgrading for high-end engine oil additives. Contact us.