Researchers working at Purdue University at West Lafayette, Indiana in the USA have developed a new dry lubricant that promises to considerably decrease wear and friction in many demanding applications.
Dry lubricants, which are sometimes called solid or liquid-free lubricants, differ from their more common liquid counterparts because there is no need for an oil medium. Instead, despite being in a solid state, a dry lubricant can reduce the friction between two sliding surfaces, usually because of a layered molecular structure with weak bonds between layers. They are often used in extreme operating environments, such as when a high temperature or low pressure precludes the use of liquid lubricants.
Solid lubricants can also have consequences for traditional greases. For example, Mobil’s Dynagear range, which can be sourced from Mobil UK stockists, uses solid lubricants to enhance the protection it provides under extreme pressure.
The new composite dry lubricant takes graphene—an ultra-thin layer of graphite, which is already commonly used as a dry lubricant—and combines it with particles of zinc oxide, which enable it to adhere to a metal surface. Finally, a polymer called polyvinylidene difluoride binds the whole thing together to form a slurry.
When testing the new lubricant on stainless-steel surfaces, the researchers observed that the film created by the new lubricant substantially reduced friction and wear. A spectroscopic analysis also revealed how the film continued to persist on wear surfaces.
An associate professor at Purdue, Vilas Pol, said about the new lubricant:
“The durability and resilience of this adhesive coating suggest exceptional potential as a dry lubricant for high load-bearing applications.”