How Much Friction Modifier To Use

The purpose of a lubricant is to reduce the amount of friction between ii surfaces. In some cases, the base oil in the oil or grease may non have plenty lubricity to perform this part sufficiently. The component metallurgy may also crave special chemistry.

For example, with worm gears, traditional farthermost-pressure or anti-wearable additives often are too chemically aggressive for the softer yellowish metals. In this situation, friction modifiers are added to increase the oil's lubricity.

Conversely, in an automatic manual, one fluid is used to provide lubrication, hydraulic ability transfer and many other functions. The clutches and friction bands within the transmission demand friction to role properly. In this instance, friction modifiers are required to smooth the transition from ane speed to some other. Otherwise, the clutches and bands would "chatter," causing damage and an irritating condition for the driver.

A number of compounds are used to alter a lubricant's coefficient of friction. These are known collectively as friction modifiers. They are designed to change the amount of energy needed to cause two surfaces to movement by ane anoth er. The different types of friction modifiers are shown in the table in a higher place.

The purpose of a friction modifier varies based on the application. In a combustion engine, the goal is to lower the amount of friction, thereby gaining fuel economy. In clutches, automatic transmissions and industrial applications, the aim is not but to control friction in order to maximize efficiency simply to reduce slippage.

To a degree, this seems a bit counterintuitive, since a lubricant's objective is to reduce friction and wear. However, there are many situations in which a certain corporeality of traction friction is required for equipment to operate properly. The friction modifiers used in these applications are non intended to increase or subtract friction but to human activity differently under specific shear conditions.

This essentially smooths the transition from a dynamic condition to a static condition, such every bit during a gear change in a transmission or the engagement of a clutch.

The vast majority of friction modifiers in use today are designed to reduce friction or increase lubricity for better fuel economy. Recently, the U.Southward. government increased fuel economy standards with the goal of raising the Corporate Average Fuel Economy (Buffet) to 54.5 miles per gallon. This number, which is double the current standard, is for gasoline engines simply, but there is a similar push for diesel engines equally well.

One fashion to attain this goal would be to reduce the viscosity of the engine oils in utilise. The challenge is lowering the viscosity while maintaining a sufficient lubricant moving picture to reduce wear and friction.

Great strides have been made in engineering science to lower the friction generated in an engine. This has increased fuel economic system. There have also been many advances in lubricant engineering science, including in the development of friction modifiers.

Friction modifiers are near efficient under boundary conditions or where metal-to-metal contact occurs. Organic friction modifiers accept long, soluble chains and a polar head. The polar head attaches to the metal surfaces. The soluble chains line up beside each other much like fibers in a carpet.

The polar heads may be comprised of phosphoric or phosphonic acids, amines, amides or carboxylic acids. The soluble chains form dense mono layers or thick, reacted viscous layers. These layers shear easily and create a relatively slippery surface.

Organic Friction Modifiers

Mechanical types of friction modifiers form layers of platelets that align with ane another, providing a reduction in friction. The nearly common of these is molybdenum dithiocarbamate (MoDTC).

These additives reduce friction past forming nano-sized single sheets dispersed in either a carbon or pyrite matrix. These nano-sized sheets are oriented in layers and slide against i some other, reducing the generated friction.

Organic molybdenum compounds accept been shown to work well in conjunction with zinc dialkyldithiophosphate (ZDDP). Used in engine oils for the ameliorate part of 80 years, ZDDP has been 1 of the well-nigh successful additives developed for oils.

It has many functions, such as serving as an antioxidant, corrosion inhibitor and anti-wear additive. These additives also have a polar head and an oil-soluble tail structure. They grade relatively thick, sacrificial boundary films that are much softer than steel or iron surfaces.

It should exist noted that non only do the polar heads of friction modifiers need to exist able to adhere to ferrous metals, only they also must be able to attach to the zinc layers that will be present due to the ZDDP.

These thick films formed by ZDDP are dependent on temperature and consist primarily of zinc, orthophosphate and polyphosphate glass, with an increasing proportion of polyphosphate chains closer to the surface.

Every bit fuel economy standards become more than stringent, more will exist required of engine oils. While the technology for friction modifiers continues to evolve, the most constructive way to better fuel economy or energy consumption is to lower the viscosity of the lubricant.

However, y'all tin only become so far before losing the hydrodynamic picture and operating in either mixed-film lubrication or boundary lubrication. It is in these 2 lubrication regimes that the use of friction modifiers becomes critical for reducing friction.

51%	of lubrication professionals use lubricants in which friction modifiers have been added, according to a contempo poll at MachineryLubrication.com

Source: https://www.machinerylubrication.com/Read/30336/friction-modifiers-use

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