Friction, wear, lubrication - the basics of nanotribology

Innovative technologies for energy efficiency & durability

Nanotribology is a branch of tribology, the science of friction. This science or technology describes and analyses how two surfaces behave in a relative movement and which practical processes take place. Basically, it is about friction and wear and therefore about the question of how wear can be prevented or at least delayed in the long term using lubricants or other methods. In terms of industry, the main focus is on motors, gears, roller bearings, guides and other moving machine elements. Incidentally, the foundations of tribology go back to the universal genius Leonardo da Vinci (1452-1519), who also worked on the design of gears and transmissions during his lifetime.

Nanotribology can reduce the costs of industrial production

Nanotribology investigates the effects of friction in the nanometre range and at the atomic level. In addition to the development of appropriate lubricants, the focus is on research into the selection of suitable materials and the treatment and coating of surfaces. Nanotribological relationships are of particular interest to industry. They can help to increase the energy efficiency of machines and at the same time reduce the costs of material use and maintenance. This conserves important raw material resources and reduces the burden on the environment. According to expert estimates, the cost of lubricants and wear caused by friction and abrasion in machines and gearboxes worldwide is in the region of one trillion euros. Nanotribology can help to significantly reduce these costs.

What is a nano coating?

A nanocoating changes the surface structure of a material at a molecular level. On contact with the substrate material, the nanostructures form a wafer-thin, water and oil-repellent layer that is firmly bonded to the surface. This prevents contamination by liquids, dust or other dirt. These properties are also known as the "lotus effect". It can be applied to almost all materials and is particularly suitable for fine-pored materials and applications that require a high degree of precision. A nano coating can withstand temperatures of up to 350° C.

Can machines also be retrofitted with a nanocoating?

In principle, nano-coating for machine parts is also possible at a later date, for example during a gearbox repair. However, it does not last as long as if it is applied directly during the production of machine parts. The nanoparticles float in a solvent. As soon as this has evaporated due to the effect of heat and air, the nanoparticles form a net-like structure that is firmly bonded to the surface of the treated parts. The components of the coating have two effects: firstly, they protect the substrate from mechanical stress caused by frictional energy, for example in the case of highly stressed gear constructions, and secondly, they ensure that foreign bodies cannot adhere thanks to the additives added.

Are nanocoatings expensive?

The question of the cost of a nano-coating is naturally one of the most important for every technical manager and responsible person in a company. Concrete sums cannot be given at this point because this depends on a number of individual factors - the type of machine or gearbox in question, the nature of the carrier material, the daily running time and stresses on the parts moving against each other. In principle, however, it can be said that a nanocoating saves costs in the long term because it reduces the use of lubricants and increases the intervals between maintenance and repairs.

The favourable alternative - a nano-coating with lubricant

Existing systems, machines and gearboxes can also be protected against wear and tear by adding certain lubricant additives. The unique product portfolio of REWITEC® serves as an example. The products developed and manufactured in Germany are compatible with all common lubricants, but can also be supplied in the customer's lubricant on request. As an additive, they are added to the lubricant of the unit during operation and transported by the lubricant to metal surfaces subject to friction. There they utilise the frictional energy and passivate the surfaces of bearings, gears and similar units by incorporating silicates, reducing roughness and thus having a lasting and positive effect on the service life, energy consumption, operational reliability and performance of gears and rolling bearings.

What effect do nanocoatings have on health and the environment?

The question of the effects on health and the environment is a key factor in favour of the use of nanocoatings, alongside the costs. According to current research, nanocoatings are neither hazardous to health nor harmful to the environment. On the contrary, their positive properties make them safer at work because they reduce the susceptibility of machines to damage.