"Game-changer" superlubricity not yet cost-effective for the lubes industry.
Friction is one of the decisive factors affecting the efficiency and service life of a mechanical system and its elimination must be the Holy Grail of the lubes industry. Over a period of time, superlubricity has been achieved in strictly controlled lab conditions using a variety of materials including graphite, graphene, silicon and diamond-like carbon film.
Cited in a recent article on superlubricity by F + L Magazine, the term was coined by Motohisa Hirano in the 1990s. He theorised a physical state where sliding friction between two contacting surfaces virtually vanishes under certain conditions.
In 2004, Martin Dienwiebel was able to demonstrate clear evidence of superlubricity when two contacting graphite surfaces are out of proportion with each other. But surface defects or roughness destroys the superlubricity in larger areas so, for a long time, his experiments were limited to nano-to micron-scales.
Argonne National Laboratory's research (2015) into solid lubrication technology has shown potential for almost limitless robust, long-lasting superlubricity in real-world industrial applications. The research was led by Dr. Anirudha Sumant who told F+L: “Solid lubricants are a very important area that even the large oil-based companies are looking at." Some companies have achieved a 10-20% reduction in friction through the introduction of graphene and other nano lubricants into their oils and additives.
In 2020, a paper published in nature.com has shown that strain engineering in practical applications has revealed that two contacted surfaces can be coated with a single layer of graphene preferably with a small residual tension, which can lead to a substantial decrease in frictional stresses.
According to F+L, there is plenty of activity in hunting the superlubricity Holy Grail, including partnerships in the oil and gas industry and auto body parts manufacturing.
While Sumant is quoted as seeing "a very bright future for this technology", he believes the key challenge to superlubricity is the tribo-chemical reaction that occurs within the oil over time. There is also concern over the cost of changing the existing infrastructure without achieving what needs to be a substantial, consistent improvement in performance.